Relevant bibliographies by topics / Photoluminescence Excitation Spectroscopy

Academic literature on the topic 'Photoluminescence Excitation Spectroscopy'

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Published: 10 December 2022
Last updated: 25 May 2024

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Journal articles on the topic "Photoluminescence Excitation Spectroscopy"

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Olsthoorn, S. M., F. A. J. M. Driessen, A. P. A. M. Eijkelenboom, and L. J. Giling. "Photoluminescence and photoluminescence excitation spectroscopy of Al0.48In0.52As." Journal of Applied Physics 73, no. 11 (June 1993): 7798–803. http://dx.doi.org/10.1063/1.353953.

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White, M. E., K. P. O'Donnell, R. W. Martin, S. Pereira, C. J. Deatcher, and I. M. Watson. "Photoluminescence excitation spectroscopy of InGaN epilayers." Materials Science and Engineering: B 93, no. 1-3 (May 2002): 147–49. http://dx.doi.org/10.1016/s0921-5107(02)00025-9.

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Sinha, S., S. Banerjee, and B. M. Arora. "Photoluminescence-excitation spectroscopy of porous silicon." Physical Review B 49, no. 8 (February 15, 1994): 5706–9. http://dx.doi.org/10.1103/physrevb.49.5706.

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Steele, A. G., and Edward C. Lightowlers. "Photoluminescence Excitation Spectroscopy of Donors in Ge." Materials Science Forum 65-66 (January 1991): 217–22. http://dx.doi.org/10.4028/www.scientific.net/msf.65-66.217.

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Horner, G. S., A. Mascarenhas, S. Froyen, R. G. Alonso, K. Bertness, and J. M. Olson. "Photoluminescence-excitation-spectroscopy studies in spontaneously orderedGaInP2." Physical Review B 47, no. 7 (February 15, 1993): 4041–43. http://dx.doi.org/10.1103/physrevb.47.4041.

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Roura, P., G. Guillot, T. Benyattou, and W. Ulrici. "Photoluminescence excitation spectroscopy of Ti3+in GaP." Semiconductor Science and Technology 6, no. 1 (January 1, 1991): 36–40. http://dx.doi.org/10.1088/0268-1242/6/1/007.

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Ristein, J., B. Hooper, S. Gu, and P. C. Taylor. "Excitation spectroscopy of photoluminescence in a-Si:H." Solar Cells 27, no. 1-4 (October 1989): 403–9. http://dx.doi.org/10.1016/0379-6787(89)90049-5.

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Siebentritt, Susanne, Niklas Papathanasiou, and Martha Lux-Steiner. "Photoluminescence excitation spectroscopy of highly compensated CuGaSe2." physica status solidi (b) 242, no. 13 (November 2005): 2627–32. http://dx.doi.org/10.1002/pssb.200541130.

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Gupta, Santosh K., Hisham Abdou, Carlo U. Segre, and Yuanbing Mao. "Excitation-Dependent Photoluminescence of BaZrO3:Eu3+ Crystals." Nanomaterials 12, no. 17 (August 31, 2022): 3028. http://dx.doi.org/10.3390/nano12173028.

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The elucidation of local structure, excitation-dependent spectroscopy, and defect engineering in lanthanide ion-doped phosphors was a focal point of research. In this work, we have studied Eu3+-doped BaZrO3 (BZOE) submicron crystals that were synthesized by a molten salt method. The BZOE crystals show orange–red emission tunability under the host and dopant excitations at 279 nm and 395 nm, respectively, and the difference is determined in terms of the asymmetry ratio, Stark splitting, and intensity of the uncommon 5D0 → 7F0 transition. These distinct spectral features remain unaltered under different excitations for the BZOE crystals with Eu3+ concentrations of 0–10.0%. The 2.0% Eu3+-doped BZOE crystals display the best optical performance in terms of excitation/emission intensity, lifetime, and quantum yield. The X-ray absorption near the edge structure spectral data suggest europium, barium, and zirconium ions to be stabilized in +3, +2, and +4 oxidation states, respectively. The extended X-ray absorption fine structure spectral analysis confirms that, below 2.0% doping, the Eu3+ ions occupy the six-coordinated Zr4+ sites. This work gives complete information about the BZOE phosphor in terms of the dopant oxidation state, the local structure, the excitation-dependent photoluminescence (PL), the concentration-dependent PL, and the origin of PL. Such a complete photophysical analysis opens up a new pathway in perovskite research in the area of phosphors and scintillators with tunable properties.
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Reuter, E. E., R. Zhang, T. F. Kuech, and S. G. Bishop. "Photoluminescence Excitation Spectroscopy of Carbon-Doped Gallium Nitride." MRS Internet Journal of Nitride Semiconductor Research 4, S1 (1999): 363–68. http://dx.doi.org/10.1557/s1092578300002738.

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We have done a comparative study of carbon-doped GaN and undoped GaN utilizing photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies in order to investigate deep levels involved in yellow luminescence (YL) and red luminescence (RL). When the GaN was excited by above-bandgap light, red luminescence (RL) centered at 1.82 eV was the dominant below-gap PL from undoped GaN, but carbon-doped GaN below-gap PL was dominated by yellow luminescence (YL) centered at 2.2 eV. When exciting PL below the band-gap with 2.4 eV light, undoped GaN had a RL peak centered at 1.5 eV and carbon-doped GaN had a RL peak centered at 1.65 eV. PLE spectra of carbon-doped GaN, detecting at 1.56 eV, exhibited a strong, broad excitation band extending from about 2.1 to 2.8 eV with an unusual shape that may be due to two or more overlapping excitation bands. This RL PLE band was not observed in undoped GaN. We also demonstrate that PL spectra excited by below gap light in GaN films on sapphire substrates are readily contaminated by 1.6−1.8 eV and 2.1−2.5 eV chromium-related emission from the substrate. A complete characterization of the Cr emission and excitation bands for sapphire substrates enables the determination of the excitation and detection wavelengths required to obtain GaN PL and PLE spectra that are free of contributions from substrate emission.
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Dissertations / Theses on the topic "Photoluminescence Excitation Spectroscopy"

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Legrand, Marie. "Advanced imaging of transient and spectral luminescence for optoelectronic characterization of photovoltaic materials." Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS066.pdf.

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La photoluminescence des absorbeurs photovoltaïques permet de connaître les phénomènes de transport de charges et les propriétés optoélectroniques dont dépendent leurs performances. Cependant, son analyse repose sur des modèles physiques qui peuvent nécessiter des hypothèses non contrôlées et des paramètres inconnus. Cette thèse explore comment l'acquisition de cartographies de photoluminescence résolues spectralement en excitation pulsée peut contribuer à la caractérisation des matériaux, tout en limitant les connaissances préalables nécessaires et en contrôlant les hypothèses et modèles sous-jacents. D'une part, nous avons développé des systèmes d'imagerie décrivant l'intensité émise en quatre dimensions : 2D spatiale, temporelle et spectrale. D'autre part, nous avons réalisé des études de variation de longueur d'onde d'excitation et discuté leur relation avec l'absorption de la lumière. Les montages déjà mis en place illustrent l’intérêt de l’analyse des différentes dimensions de la lumière. Un imageur hyperspectral, fournissant le spectre dans chaque pixel, permet de caractériser les propriétés du matériau et les porteurs de charge générés. En complément, l'imagerie résolue en temps donne un aperçu des mécanismes de transport. Nous passons en revue et proposons différentes techniques pour obtenir des données 4D correspondant à l'évolution temporelle du spectre dans chaque pixel d'une image I_PL (x,y,énergie,temps). Parmi elles, l’imagerie monopixel utilise la modulation spatiale de la lumière pour reconstruire des cartographies spatiales. Trois techniques de mesure ont été développées sur le principe de l'imagerie à pixel monopixel. Elles correspondent à différents schémas d'échantillonnage dans l'espace 4D, en se concentrant sur les dimensions temporelles et spectrales qui sont atteintes avec de hautes résolutions. Leur mise en œuvre a été un défi car la photoluminescence correspond à des conditions de faible luminosité, et plus les résolutions sont élevées, plus la sensibilité est faible. Chaque dimension de la lumière impliquée doit être reconstruite avec précision tout en étant intriquée dans le processus d'acquisition. En particulier, l'impact de la diffraction et des interférences dues au modulateur spatial de lumière a été étudié. Ce travail instrumental a tout d'abord donné lieu à un système d’imagerie multimodale résolue temporellement et spectralement (2x3D). Il a été appliqué au suivi des mécanismes induits par la lumière dans les pérovskites, et qui conduisent à des changements dans de spectre et de dynamique. En second lieu, nous avons réalisé un outil d’imagerie 4D, illustré sur un échantillon d'arséniure de gallium. L'évolution conjointe de la photoluminescence dans les dimensions temporelle, spatiale et spectrale est observée en raison du remplissage des bandes et de la diffusion. Enfin, une méthode basée sur des algorithmes de segmentation d’image est proposée. Une cartographie spatiale est obtenue par imagerie mono-pixel, à partir de laquelle les zones d'intérêt sont déterminées avant d’y mesurer le déclin avec de hautes résolutions temporelles et spectrales. Un échantillonnage de la photoluminescence est obtenu avec un rapport signal/bruit élevé permettant son application à une variété d’échantillons et de conditions d'injection. Ces deux dernières approches sont uniques à notre connaissance et permettent d'obtenir une variation du PL dans les domaines combinés spatial, temporel et spectral. De plus, nous avons mis en place une méthodologie pour réaliser des études de longueur d'onde d'excitation sur l'imageur hyperspectral. Ainsi, l'absorptivité relative locale d’un échantillon de pérovskite inhomogène est obtenue sur une large gamme spectrale à partir d’une analyse combinée des spectres d'émission et d'excitation. Les mesures de réflectivité complétant cette étude fournissent des informations optiques et topologiques permettant d'affiner l'interprétation des cartographies de photoluminescence
Photoluminescence characterization of photovoltaic absorbers provides the charge transport phenomena and the optoelectronic properties on which their performance relies. However, their obtention is based on physical models and may require uncontrolled assumptions and unknown parameters. This thesis explores how acquiring spectrally resolved maps of photoluminescence in pulsed excitation can contribute to material characterization while limiting the necessary prior knowledge and controlling underlying hypotheses and models. On the one hand, we developed imaging systems describing the emitted intensity in four dimensions: 2D spatial, temporal and spectral. On the other hand, we performed excitation wavelength variation studies and investigated their relationship with light absorption. Maps of intensity can be acquired by pixelated detectors or non-imaging detectors, as in Single-pixel imaging. This approach employs spatial light modulation to reconstruct images and is particularly relevant to obtain multidimensional images. It is thus of interest for photoluminescence as each dimension brings information, as demonstrated by the setups already in use. A hyperspectral imager, providing the spectrum in each pixel, allows the characterization of material properties and the charge carriers generated. Complementarily, time-resolved imaging gives an insight into the transport mechanisms. We review and propose different techniques to obtain 4D data corresponding to the temporal evolution of the spectrum in each pixel of an image I_PL (x,y,energy,time). It provides the correlation between temporal and spectral dimensions, which was not available in the lab previously. Three measurement approaches were developed based on the principle of single-pixel imaging. They correspond to different sampling schemes in the 4D space, focusing on temporal and spectral dimensions that are reached with high resolutions. Their implementation was challenging as photoluminescence corresponds to low light conditions, and the higher the resolutions, the lower the sensitivity. Each dimension of light involved must be accurately reconstructed while entangled in the acquisition process. Particularly, the impact of diffraction and interferences due to the spatial light modulator has been investigated. This instrumental work allowed, first of all, combined time and spectrally resolved imaging (2x3D) of perovskite. It allowed monitoring of light-induced mechanisms that modify the photoluminescence spectrum and dynamics. Secondly, it has led to the characterization in 4D of the emission of a gallium arsenide wafer. The joint evolution of the signal in temporal, spatial, and spectral dimensions is observed due to band-filling and diffusion. At last, a workflow based on pixel clustering algorithms is proposed. A spatial map is obtained by single-pixel imaging, from which areas of interest are determined before the decay is obtained with high temporal and spectral resolutions. It allows an original sampling of photoluminescence with a high signal-to-noise ratio enabling its application to various samples and injection conditions. These last two approaches are unique to the best of our knowledge and provide photoluminescence variation in the combined spatial, temporal, and spectral domains. In addition, we have set up a methodology to perform excitation wavelength studies on the hyperspectral imager. It was demonstrated on an inhomogeneous perovskite sample from which the local relative absorptivity is obtained on a wide spectral range by combined analysis of the emission and excitation spectra. Reflectivity measurements completing this study provide optical and topological information allowing us to refine the interpretation of photoluminescence maps
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Jaló, Daniel Jorge Pires. "Structural and optical characterization of Mg doped GaAs nanowires and the impact of the functionalization with Au nanoparticles." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/17415.

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Mestrado em Engenharia Física
GaAs, nanowires, nanotechnology, semiconductors, spectroscopy, photoluminescence, photoluminescence excitation, cathodoluminescence, Raman, nanoparticles, nanorods, functionalization, image charge effect.
O presente trabalho teve como objetivos principais: i) estudar o efeito da dopagem com Mg nas propriedades óticas e estruturais de nanofios de GaAs crescidos em substratos de Si(111); ii) avaliar as modificações nas propriedades óticas dos nanofios em resultado da funcionalização com nano varetas metálicas de ouro. No estudo foram utilizadas várias técnicas de caracterização: a microscopia eletrónica de varrimento, espetroscopia de Raman, fotoluminescência, excitação da fotoluminescência e catodoluminescência. Independentemente da concentração do dopante, os resultados experimentais da espetroscopia de Raman confirmaram a coexistência das fases de blenda de zinco (BZ) e de wurtzite (WZ) ao longo do eixo de crescimento dos nanofios. Espectroscopia de fotoluminescência revelou emissões abaixo da energia de hiato do GaAs na fase BZ. A natureza indireta das emissões, característica de um alinhamento tipo II das bandas eletrónicas da BZ e WZ, foi confirmada pela dependência da energia do máximo de emissão com a raiz cúbica da potência de excitação (P1/3). Os resultados experimentais da dependência da intensidade de PL com a potência revelaram que as emissões principais observadas são compatíveis com os modelos de recombinação de portadores free-to-bound ou a pares dador-aceitador na amostra menos dopada, e recombinações de excitões ligados a impurezas na amostra mais dopada. Os resultados de catodoluminescência, à temperatura ambiente, confirmaram a existência de diferentes emissões ao longo do eixo de crescimento dos fios, confirmando o politipismo estrutural. As emissões observadas em catodoluminescência concordam com as principais componentes identificadas em fotoluminescência. No estudo da fotoluminescência com a temperatura foram identificados diferentes canais de desexcitação não radiativa, cujos elevados valores de energias de ativação são consistentes com nanofios contendo segmentos muito finos de BZ. A funcionalização dos fios com nanovaretas metálicas de Au conduziu a um pequeno desvio para o azul na localização energética do máximo de emissão, mostrando que é possivel modificar as propriedades óticas dos nanofios de GaAs.
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Posavec, Tony. "An Investigation into the Fluorescence of Polymers." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1499353221343727.

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Chastaingt, Bruno. "Spectroscopie d'hétérostructures ultra-minces appliquée à l'étude de l'interface GaAa/AlAs." Nice, 1993. http://www.theses.fr/1993NICE4694.

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L'objectif des travaux décrits dans ce mémoire est de rechercher le lien entre les propriétés de recombinaisons dans les hétérostructures de type GaAs/AlAs et la structure de l'interface. L'observation de variations des énergies de confinement dans les puits quantiques directs GaAs/(al,ga)as lies aux choix des températures de croissance amène une interrogation sur la nature des processus qui entrainent l'introduction d'un désordre aux interfaces (ségrégation verticale ou démixtion d'alliage) et conduise à approfondir l'étude de puits quantiques à double barrière GaAs/AlAs/(al,ga)as ou les épaisseurs de couches d'AlAs et de GaAs sont réduites à quelques monocouches. Les études expérimentales (excitation de photoluminescence, photoluminescence résolue en temps, photoluminescence sous pression hydrostatique) associées à une modélisation en fonction enveloppe démontre la diversité des alignements des niveaux confines et apporte des informations sur la localisation des électrons dans une ou deux monocouches d'AlAs. Ces expériences expliquent les processus de transferts entre les niveaux associes aux minima xxy et xz ou de capture sur les donneurs ainsi que le phénomène de couplage entre les états de GaAs et x d'AlAs. L'existence d'un confinement latéral est démontrée lorsque ces mêmes structures sont élaborées sur surfaces vicinales. Dans ces conditions l'analyse des recombinaisons de structures ou la couche d'AlAs est réduite à une monocouche révèle l'action des fluctuations des largeurs de terrasse sur les propriétés de recombinaisons
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Steveler, Émilie. "Etude des mécanismes de photoluminescence dans les nitrures et oxydes de silicium dopés aux terres rares (Er, Nd)." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0109/document.

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Ce travail de thèse est dédié à l'étude des transitions radiatives dans les matériaux de nitrure et d'oxyde de silicium dopés aux ions de terres rares (Er3+, Nd3+). La caractérisation optique des films minces élaborés par évaporation thermique est basée sur la spectroscopie de photoluminescence. Les études menées s'inscrivent dans la recherche de processus d'excitation indirecte des ions Er3+ et Nd3+ dans des matrices à base de silicium. Dans les nitrures et oxynitrures de silicium, un processus de transfert d'énergie permettant l'excitation indirecte des ions Er3+ est mis en évidence. Pour les couches minces amorphes, le couplage est attribué à des états électroniques localisés dans la bande interdite de la matrice. Pour les films recuits à haute température, les nanocristaux de silicium (nc-Si) jouent un rôle majeur dans l'excitation indirecte de l'erbium. Dans les matrices d'oxyde de silicium, l'existence de processus d'excitations directe et indirecte des ions Nd3+ est démontrée. Pour les films amorphes, l'excitation indirecte du Nd se fait via des états électroniques localisés dans la bande interdite de la matrice. Pour les films recuits au-delà de 1000 °C, les nc-Si jouent le rôle de sensibilisateurs pour les ions Nd3+. Les résultats suggèrent que l'excitation indirecte des ions Nd3+ grâce aux états localisés dans la bande interdite de la matrice pourrait être plus efficace que l'excitation via les nc-Si
This thesis is devoted to the study of radiative transitions in rare-earth (Er, Nd) doped silicon oxide and silicon nitride thin films. The optical characterization of thin films prepared by thermal evaporation is based on photoluminescence spectroscopy. In this work, we investigate indirect excitation processes of Er3+ and Nd3+ ions in silicon based materials. In silicon nitride and silicon oxinitride, an energy transfer leading to the indirect excitation of Er3+ ions is demonstrated. For amorphous samples, the sensitization of Er3+ ions is attributed to localized electronic states in the matrix bandgap. For samples annealed at high temperature, silicon nanocrystals play a major role in the indirect excitation of erbium. In silicon oxide thin films, we evidences that both direct and indirect excitation processes of Nd3+ ions occur. For amorphous samples, indirect excitation occurs thanks to localized electronic states in the matrix bandgap. For samples annealed at temperatures above 1000 °C, silicon nanocrystals are sensitizers of Nd3+ ions. Results suggest that indirect excitation thank to localized states in the matrix bandgap could be more efficient than indirect excitation thanks to silicon nanocrystals
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Hsieh, Meng-hsueh, and 謝孟學. "Photoluminescence excitation spectroscopy on InGaN/GaN multiple quantum wells grown on silicon substrates." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/54874u.

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碩士
國立中山大學
材料科學研究所
95
We study the optical properties of InGaN/GaN multiple quantum wells grown on silicon (111) substrate with different buffer layers. Because of the lattice mismatch and mismatch in thermal expansion coefficient, there exists stresses in the nitride sample grown on silicon substrates, which influence the growth properties and optical properties. A set of buffer layers was proposed in order to reduce the stress in our samples. The influence on optical properties is investigated in our work. In Raman spectra, we observed the characteristic phonon mode of GaN. According to the variation of E2 mode, the stress can be estimated. From our results, growing buffer layers can effectively reduce the stress in the sample. From temperature dependent and power dependent photoluminescence（PL) measurement, we found that appropriate buffer layers bring about less stress and better efficiency of luminescence. There are absorption of GaN and some vibrational behaviors in PLE spectra. According to the stokes shift calculated from temperature dependence PL and PLE spectra, we infer that the mechanism of recombination is not only carrier localization. The recombination is involved with the interaction of carriers and longitudinal optical phonons, and the stokes shift is independence on temperature.
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Lu, Shi Shiang, and 呂世香. "The Electronic Structure of Semiconductor Microstructures: Its Calculation and Characterization by Photoluminescence Excitation Spectroscopy." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/44030362059539142714.

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Kao, Chia-wei, and 高嘉維. "Surface photovoltage spectroscopy, photoluminescence, and photoluminescence excitation characterization of InAs/GaAs quantum dots structures with InxGa1-xAs over grown layer." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/4tw396.

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碩士
國立臺灣科技大學
電子工程系
94
Surface photovoltage spectroscopy (SPS), photoluminescence (PL) and photoluminescence excitation (PLE) techniques have been used to characterize the self-assembled InAs/GaAs quantum dots (QDs) structures with and without InGaAs overgrown layers grown by solid source molecular beam epitaxy (SSMBE). Signals from barrier, wetting layer (WL), overgrown layer, ground state and excited states of the QDs have been observed and identified. The effects of the InGaAs overgrowth layer have been studied in detail. The information on the decomposition of the InGaAs layer has been obtained from the electronic transition properties of the quantum well (QW) formed by the InAs WL and the InGaAs layer. The effects of the InGaAs overgrowth layer have been studied in detail. The observed reduction in the energy splitting in the energy splitting of the heave- and light-hole in the wetting layer indicate a partial strain relaxation due to the InGaAs overgrown layer. The red shifts of the ground state and excited states transition energies of QDs have been attributed to the altered strain distribution and increase of QD size. The optical properties of the InAs QDs, WL, QW, and GaAs were studied with the fitting parameters using Varshni’s equation. The SPS has been shown to be a complementary technique to PL and PLE, and can be used for nondestructive characterization of self-assembled QDs structures.
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Das, Sarthak. "Tailoring excitonic complexes in layered materials." Thesis, 2021. https://etd.iisc.ac.in/handle/2005/5747.

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Layered transition metal dichalcogenides (TMDCs) host a variety of strongly bound exciton complexes that control the optical properties in these materials. Apart from spin and valley, layer index provides an additional degree of freedom in a few-layer-thick lm. While in the 1H monolayer TMD inversion symmetry is broken, and the reflection symmetry is maintained but, in the bilayer, it is reversed. Trions are excitonic species with a positive or negative charge, and thus, unlike neutral excitons, the flow of trions can generate a net detectable charge current. Trions under favourable doping conditions can be created in a coherent manner using resonant excitation. The neutral biexciton (bound state of two excitons) can assemble further to create a charged state with another electron or hole. Generally, in W-based TMDs these ve-particle quinton states dominate the population density and this can also be engineered to produce photocurrent at cryogenic temperature. In the firrst work, we show that in a few-layer TMDC lm, the wave functions of the conduction and valence-band-edge states contributing to the K(K0) valley are spatially con ned in the alternate layers - giving rise to direct (quasi-)intralayer bright exciton and lower-energy interlayer dark excitons. Depending on the spin and valley con figuration, the bright-exciton state is further found to be a coherent superposition of two layer- induced states, one (E type) distributed in the even layers and the other (O type) in the odd layers. The intralayer nature of the bright exciton manifests as a relatively weak dependence of the exciton binding energy on the thickness of the few-layer lm, and the binding energy is maintained up to 50 meV in the bulk limit - which is an order of magnitude higher than conventional semiconductors. Fast Stokes energy transfer from the intralayer bright state to the interlayer dark states provides a clear signature in the layer-dependent broadening of the photoluminescence peak and plays a key role in the suppression of the photoluminescence intensity observed in TMDCs with thickness beyond a monolayer. In the second work, we show that bilayer WS2 exhibits a quantum con ned Stark effect (QCSE) that is linear with the applied out-of-plane electric field, in contrast to a quadratic one for a monolayer because of the contrasting symmetries between monolayer and bilayer. The interplay between the unique layer degree of freedom in the bilayer and the field-driven partial interconversion between intralayer and interlayer excitons generates a giant tunability of the exciton oscillator strength. This makes bilayer WS2 a promising candidate for an atomically thin, tuneable electro-absorption modulator at the exciton resonance, particularly when stacked on top of a graphene layer that provides an ultrafast nonradiative relaxation channel. By tweaking the biasing confi guration, we further show that the excitonic response can be largely tuned through electrostatic doping, by efficiently transferring the oscillator strength from neutral to charged exciton. In the third and fourth work, we demonstrate interlayer charge transport from top few-layer graphene to bottom monolayer graphene, mediated by a coherently formed trion state using a few-layer graphene/monolayer WS2/monolayer graphene vertical het- erojunction. This is achieved by using a resonant excitation and varying the sample temperature. The resulting change in the WS2 bandgap allows us to scan the excitation around the exciton-trion spectral overlap with high spectral resolution. By correlating the vertical photocurrent and in situ photoluminescence features at the heterojunction as a function of the spectral position of the excitation, we show that (1) trions are anoma- lously stable at the junction even up to 463 K due to enhanced doping, and (2) the photocurrent results from the ultrafast formation of a trion through exciton-trion coher- ent coupling, followed by its fast interlayer transport. Further, the resonant photocurrent thus generated can be effectively controlled by a back gate voltage applied through the incomplete screening of the bottom monolayer graphene, and the photocurrent strongly correlates with the gate dependent trion intensity, while the non-resonant photocurrent exhibits only a weak gate dependence. We estimate a sub-100 fs switching time of the device. In the final work, we have used the pulsed laser excitation to create the quinton states in monolayer WS2 while resonantly exciting the exciton and trion states at low temperature. Strong light absorption by the charged biexciton under spectral resonance, coupled with its charged nature, makes it intriguing for photodetection - an area that is hitherto unexplored. Using the high built-in vertical electric eld in an asymmetrically designed few-layer graphene encapsulated 1L-WS2 heterostructure, here we report, for the rst time, a large, highly nonlinear photocurrent arising from the strong absorption by two charged biexciton species under zero external bias (self-powered mode). Time- resolved measurement reveals that the photoresponse is ultra-fast, on the order of sub-5 ps. By using single- and two-color photoluminescence excitation spectroscopy, we show that the two biexcitonic peaks originate from bright-dark and bright-bright exciton-trion combinations. The possibility of electrical manipulation and detection of a charged exciton (trion) before its radiative recombination makes it promising for excitonic devices. The demon- stration of coherent formation, high stabilization, vertical transportation, and electrical detection of trions marks a step toward room-temperature trionics. Following the same the ve-particle charged quinton can also be efficiently generated and electrically de- tected. They can be used in electrical detection of constituting bright and dark states and quantum manipulation of the coupled spin-valley physics. Such innate nonlinearity in the photocurrent due to its biexcitonic origin, coupled with the ultra-fast response due to swift inter-layer charge transfer exempli fies the promise of manipulating many- body effects in monolayers. Also, the findings are prospective toward highly tunable, atomically thin, compact, and light on chip, re-confi gurable components and promising for several applications such as higher harmonics generation of the modulating signal, receiver design in microwave photonics and visible light communication, square-law cir- cuits, and also in nonlinear next generation optoelectronics.
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Wilson, Mark. "Investigations into the Optical Properties of Individual, Air-Suspended, Single-Walled Carbon Nanotubes." Thesis, 2008. http://hdl.handle.net/1974/1485.

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Single-walled carbon nanotubes are naturally-forming nanostructures that have attracted considerable recent research interest due to their unique opto-electronic properties and comparative ease of fabrication. Two-thirds of nanotube species are semiconductors due to symmetry conditions imposed by their pseudo-one-dimensional tubular structure, and exhibit band-gap photoluminescence when isolated from their environment. Despite their elegant structural simplicity, fundamental properties of carbon nanotubes, such as their intrinsic quantum efficiency, non-linear excitonic recombination mechanisms, and the role of environmental effects, continue to be disputed in the literature. The design of an apparatus capable of observing nanotube photoluminescence is presented, along with conclusive proof of the observation of a single (9,8)-chirality nanotube in the form of spectral, spatial, and polarization-dependent measurements. The dependance of the excitation and emission spectra of a single nanotube on the excitation intensity is explored and the emission spectra found to be described by a Gaussian peak function, in contrast to previously-reported results. The unexpected ability to cause redshifts in the emission spectrum via the ambient humidity is discovered, which has consequences on experimental best practices. Photoluminescence quantum efficiencies are measured to be 4±2% and 13±6% for two different nanotubes. This is at the high end of the range for comparable literature results, and supports the validity of a recent literature value for the effective atomic absorption coefficient for carbon, AC=1.6×10^−3nm^2, which is ten times greater than previous literature values. Pulsed power dependence studies show that the PL emission undergoes ‘hard’ saturation at an excitation intensity of 0.5×10^12photons/pulse/cm2, which is at least 100 times lower than previous reports and provides insight into non-linear decay dynamics. A novel theoretical model is developed to explain this saturation process, which yields an absorption co-efficient of AC=1.2±0.3×10^−3nm^2 as a fit parameter. Time-resolved photoluminescence dynamics are explored using femtosecond excitation correlation spectroscopy. Results suggest that the one-body decay processes are bi-exponential, with time constants of 31±4ps and 313±61ps, but also highlight the limitations of this technique in observing the expected very rapid (~1 ps) two-body Auger recombination process.
Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2008-09-26 16:23:40.81
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Book chapters on the topic "Photoluminescence Excitation Spectroscopy"

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HAEGEL, NANCY M., and LEI WANG. "PHOTOLUMINESCENCE EXCITATION SPECTROSCOPY OF POROUS SILICON." In Porous Silicon, 219–33. WORLD SCIENTIFIC, 1994. http://dx.doi.org/10.1142/9789812812995_0011.

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W. Kenney III, John, Joshua Jacobsen, Amanda Renfro, Isaac Muñoz, and Ruth Christian. "Time-Dependent Photoluminescence and Photoluminescence Excitation in Exciton Systems and Related Phenomena." In Quantum Field Theory [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.106888.

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The term “exciton” covers an extremely diverse range of materials, phenomena, processes, interactions, and experimental techniques. This review provides a general introduction-with selected descriptive examples-of excitonic systems with an emphasis on excitonic photoluminescence and photoexcitation spectroscopy in the ultrafast time-resolved femtosecond time domain.
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Henderson, B., and G. F. Imbusch. "Experimental techniques." In Optical Spectroscopy of Inorganic Solids, 258–314. Oxford University PressOxford, 2006. http://dx.doi.org/10.1093/oso/9780199298624.003.0006.

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Abstract Tms book is concerned with the optical properties of inorganic solids which have a measurable forbidden energy gap between the valence and conduction bands. The bandgap may be small, as in some semiconductors, or large, as in materials such as diamond and aluminium oxide. Both impurity ions and defects may have energy levels in the gap, and transitions may be excited between these gap levels or between band states and the gap levels. Many experimental techniques have been used to investigate such transitions, those of longest standing being optical absorption spectroscopy and photoluminescence spectroscopy. In crystalline materials absorption and luminescence transitions may be strongly polarized due to the electronic centre occupying a low-symmetry site in the solid or to the effects of an external perturbation (e.g. magnetic field, electric field, or uniaxial stress). Analysis of the luminescence decay after pulsed excitation may indicate the dipole nature of the radiative process (Section 2), and the occurrence of dynamic processes such as excitation transfer between centres (Section l0.1).
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Conference papers on the topic "Photoluminescence Excitation Spectroscopy"

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Brackmann, Stefan, Srumika Konde, Katharina Gejer, Marina Gerhard, and Martin Koch. "The right excitation wavelength for microplastics detection via photoluminescence." In Applied Industrial Spectroscopy. Washington, D.C.: Optica Publishing Group, 2023. http://dx.doi.org/10.1364/ais.2023.am2a.5.

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The identification of microplastic particles by photoluminescence could be a low-cost addition to established spectroscopic methods. Here, we investigate which excitation wavelength is optimal for such investigations.
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DeLong, M. C., R. A. Hogg, D. J. Mowbray, M. Hopkinson, M. S. Skolnick, P. C. Taylor, J. M. Olson, Sarah R. Kurtz, and A. E. Kibbler. "Photoluminescence and photoluminescence excitation spectroscopy in ordered and disordered Ga0.52In0.48P." In Photovoltaic advanced research and development project. AIP, 1992. http://dx.doi.org/10.1063/1.42885.

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Keitel, Robert C., Felipe V. Antolinez, Stefan Meyer, Raphael Brechbühler, Maria del Henar Rojo Sanz, and David J. Norris. "Photoluminescence Excitation Spectroscopy on Individual Quantum Emitters." In Internet Conference for Quantum Dots. València: Fundació Scito, 2020. http://dx.doi.org/10.29363/nanoge.icqd.2020.046.

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Rakovich, Yury, Laura Walsh, Louise Bradley, John F. Donegan, Dmitri Talapin, Andrey Rogach, and Alexander Eychmueller. "Size-selective photoluminescence excitation spectroscopy in CdTe quantum dots." In OPTO Ireland, edited by Thomas J. Glynn. SPIE, 2003. http://dx.doi.org/10.1117/12.463693.

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Moore, James E., Xufeng Wang, Elizabeth K. Grubbs, Jennifer Drayton, Steve Johnston, Dean Levi, Mark S. Lundstrom, and Peter Bermel. "Photoluminescence excitation spectroscopy characterization of cadmium telluride solar cells." In 2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC). IEEE, 2016. http://dx.doi.org/10.1109/pvsc.2016.7750030.

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Jackson, M. K., M. B. Johnson, D. H. Chow, J. Soderstrom, T. C. McGill, and C. W. Nieh. "Electron Tunneling Time Measured by Photoluminescence Excitation Correlation Spectroscopy." In Picosecond Electronics and Optoelectronics. Washington, D.C.: Optica Publishing Group, 1989. http://dx.doi.org/10.1364/peo.1989.trt124.

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The tunneling time for electrons to escape from the lowest quasi-bound state in the quantum wells of GaAs/AlAs/GaAs/AlAs/GaAs double-barrier heterostructures with barriers between 16 Å and 62 Å has been measured at 80 K using photoluminescence excitation correlation spectroscopy. The decay time for samples with barrier thicknesses from 16 Å (≈ 12 ps) to 34 Å (≈ 800 ps) depends exponentially on barrier thickness, in good agreement with calculations of electron tunneling time derived from the energy width of the resonance. Electron and heavy-hole carrier densities are observed to decay at the same rate, in contrast to resonance-width calculations that indicate that heavy-hole tunneling times should be much longer than those for electrons. Reasons for this observation are discussed. Similar measurements in biased structures showing negative differential resistance are described.
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Jagrati, Akshay Kumar, Shalendra Kumar, Ravi Kumar, and Ankush Vij. "Photoluminescence emission and excitation spectroscopy of Bi doped SrS nanophosphors." In NATIONAL CONFERENCE ON RECENT ADVANCES IN EXPERIMENTAL AND THEORETICAL PHYSICS (RAETP-2018). Author(s), 2018. http://dx.doi.org/10.1063/1.5051277.

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Fischer, Moritz, Ali Sajid, Alexander Hötger, Kristian S. Thygesen, Sanshui Xiao, Martijn Wubs, Alexander Holleitner, and Nicolas Stenger. "Low-temperature spectroscopy of single-photon emitters in irradiation-engineered hexagonal boron nitride." In Conference on Lasers and Electro-Optics/Pacific Rim. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/cleopr.2022.ctua7a_03.

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To identify the microscopic origin of single-photon emitters in hexagonal boron nitride, we perform low-temperature spectroscopy. We observe strong photoluminescence at two different excitation lasers that hint at a phonon-assisted excitation scheme.
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Choksy, D. J., E. A. Szwed, L. V. Butov, K. W. Baldwin, and L. N. Pfeiffer. "Fermi edge singularity in photoluminescence excitation spectra of neutral ultracold electron-hole system." In CLEO: Fundamental Science. Washington, D.C.: Optica Publishing Group, 2023. http://dx.doi.org/10.1364/cleo_fs.2023.fw3n.8.

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We observed a strong enhancement of spatially direct absorption at the Fermi energy of ultracold electron-hole system in separated electron and hole layers, evidencing Fermi-energy excitons. Absorption was probed by photoluminescence excitation spectroscopy.
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BONDARENKO, V., N. KAZUCHITS, M. BALUCANI, and A. FERRARI. "PHOTOLUMINESCENCE EXCITATION SPECTROSCOPY OF ERBIUM INCORPORATED WITH IRON IN OXIDIZED POROUS SILICON." In Physics, Chemistry and Application of Nanostructures - Reviews and Short Notes to Nanomeeting 2003. WORLD SCIENTIFIC, 2003. http://dx.doi.org/10.1142/9789812796738_0061.

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