Academic literature on the topic 'Screen print dopant sources'

Purpose The purpose of this study is comparison of the diffusion processes performed using the commercial available dopant paste made by Filmtronics and the original prepared liquid dopant solution. To decrease prices of industrially produced silicon-based solar cells, the new low-cost production processes are necessary. The main components of most popular silicon solar cells are with diffused emitter layer, passivation, anti-reflective layers and metal electrodes. This type of cells is prepared usually using phosphorus oxychloride diffusion source and metal pastes for screen printing. The diffusion process in diffusion furnace with quartz tube is slow, complicated and requires expensive equipment. The alternative for this technology is very fast in-line processing using the belt furnaces as an equipment. This approach requires different dopant sources. Design/methodology/approach In this work, the diffusion processes were made for two different types of dopant sources. The first one was the commercial available dopant paste from Filmtronics and the second one was the original prepared liquid dopant solution. The investigation was focused on dopant sources fabrication and diffusion processes. The doping solution was made in two stages. In the first stage, a base solution (without dopants) was made: dropwise deionized (DI) water and ethyl alcohol were added to a solution consisting of tetraethoxysilane (TEOS) and 99.8 per cent ethyl alcohol. Next, to the base solution, orthophosphoric acid dissolved in ethyl alcohol was added. Findings Diffused emitter layers with sheet resistance around 60 Ω/sq were produced on solar grade monocrystalline silicon wafers using two types of dopant sources. Originality/value In this work, the diffusion processes were made for two different types of dopant sources. The first one was the commercial available dopant paste from Filmtronics and the second one was the original prepared liquid dopant solution.

Instead of selective emitter technology we investigate an alternative way to optimize contact formation and increased blue responsivity of highly resistive emitter solar cells using screen print technology for the deposition of the frontside metallization grid. We show with the aid of an inline doping/diffusion set-up at Blue Chip Energy that tuning the emitter doping profile is an alternative way to reduce the effect of Auger recombination in the spectral range from 300 nm to 600 nm. By properly choosing the process conditions we were able to minimize the detrimental effect of the low surface concentration of the dopant on the contact resistance. Due to improved blue light responsivity a significant gain in short circuit current Jsc was achieved. This and a reduced reverse saturation current I00E yielded a higher open circuit voltage VOC and an increase of cell efficiency from 17.6 %-avg to more than 17.9 %-avg.

Abstract Nationwide surveys of researchers in Finland in 2007 and 2016 distributed with the assistance of FinELib, the Finnish national consortium, show that researchers use a growing range of sources to find and access scholarly articles and that some reading patterns are changing. The percentage of articles found by searching and browsing are decreasing, while researchers are using more social ways to locate articles. Research social networking sites are rated as important to their work. They read more on-screen, although still print some material out for final reading. Reading patterns for books are different, as researchers still rely more on printed books than e-books, in spite of an increase in e-book collections through their libraries. This study shows a continuous process of incremental change, enabled by changes in scholarly publishing, social networking, and library collection decisions. More changes can be expected, as researchers adopt systems and patterns that fit with their work patterns and make the finding, locating, and reading of scholarly materials easier. Libraries must both lead and adapt to these new reading patterns by providing links and access to a variety of journal services and by maintaining a balance of print and e-book collections.

Objective – To observe and compare the strategies that undergraduate science students use to perform information retrieval tasks in e-books and in print books. Design – Qualitative analysis, employing a “prompted think-aloud” methodology and thematic analysis. Setting – Taylor Library (serving the Faculty of Science), University of Western Ontario, London, Ontario, Canada. Subjects – Twenty undergraduate science students (11 females, 9 males) who had completed at least two years of study in Faculty of Science programs at the University of Western Ontario. Methods – Participants for the study were recruited through informational posters in Taylor Library, science departments, and in undergraduate science classes. Participants were assigned fact-finding tasks in e-book and print versions of eight health, computer science, and engineering textbooks and handbooks available in the Taylor Library. Book titles and tasks are included in a table in the study. Each student completed four tasks using e-books and four tasks using print books. Half of the participants performed tasks in print books first, and half began with tasks in e-books. Print books were “pre-selected” for each participant. The e-books were all from the same platform: Electronic Book Library. Participants were provided with a laptop computer to access the e-book versions, and a list of questions or facts to locate within each book. Following the methodology of Cotton & Gresty (2006), one researcher prompted students to verbalize actions while performing assigned tasks. A second researcher captured audio and video of the laptop screen as students individually conducted their e-book searches. A third researcher took notes on each session. An exit survey was given to each participant, asking about previous use, knowledge, and attitudes towards e-books. Thematic analysis was then used to examine the collected data. Main Results – Researchers identified four major themes from the data with regard to use of print versus e-books: linear/non-linear strategies; tangible/intangible aspects of books; met/unmet expectations; and transferable/non-transferable behaviours. Researchers found that participants tended to search print books in a linear fashion, whereas they approached e-books non-linearly. Physicality and familiarity with print books helped participants more readily find answers, compared to e-books, where students tried less successfully to mimic techniques used in print books to locate requested information. Participants used indexes in print books, versus e-books where they did not quickly identify the e-books as having them. The students expected that the e-books would behave as other web-based/online sources or search engines would (such as Google books), and commented that they did not. Transferable actions between print and e-books included developing and using keywords for searching. Conclusion – The authors of this study found that student participants did not know how to navigate the e-books presented to them compared with their print counterparts. There was a lack of awareness on the part of participants about e-books in general: the students were unaware that e-books were available through the library catalogue; they did not know that e-books have indexes as print books do; and did not know the differences among platforms offered by the library. All of these facts point to the importance of user education. The authors note the importance of testing of e-book platforms by students, faculty, and librarians prior to committing to purchase particular platforms. The authors note that more research is needed on user interaction with e-books, how e-books are used to assimilate information, and how groups other than undergraduates search e-books.

A review of: Rowland, Ian, David Nicholas, Hamid R. Jamali, and Paul Huntington. “What do Faculty and Students Really Think about E-books?” Aslib Proceedings: New Information Perspectives; 59.6 (2007): 489-511. Objective – To assess academic users’ awareness, perceptions and levels of use of e-books. Also to discover the purposes for which e-books were used and identify the most effective library marketing strategies for e-books. Design – Survey. Setting – University College London (UCL). Subjects – 1,818 UCL staff and students. Methods – In November 2006, staff and students of UCL were asked to participate in an online survey, administered using SurveyMonkey software. The survey ran November 1-18, 2006. Survey results were analysed using Software Package for Social Sciences (SPSS). Main Results – The response rate to the survey was at least 6.7%. A total of 1,818 completed surveys were received from approximately 27,000 potential respondents, although it is not known whether all e-mails announcing the survey were successfully delivered. No statistically significant differences were found between the demographic profile of the survey sample and the profile of the total UCL population. Data regarding e-book usage were collected from the sub-group of respondents who were existing e-book users, and data regarding use of print collections and book discovery were collected from all respondents. Forty-four per cent of respondents had used e-books, with age a good predictor of usage. However additional data analysis revealed complex demographic interactions underlying e-book usage, making broad generalisations too simplistic. Of existing e-book users, 61% sourced e-books independently of the UCL library. Deeper analysis showed that men were more “library independent” than women and doctoral students were more so than other students and staff. Forty-eight per cent of existing e-book users preferred reading from a screen rather than paper, with men more likely to read from a screen than women, and undergraduates more likely to do so than other groups. Responses to questions about the purpose of reading showed that existing e-book users consulted e-books primarily for work and study, and tended to obtain these from libraries. They were less likely to use e-books for leisure, but if they did so, were likely to obtain them from non-library sources. E-books were compared to traditional print across a range of factors and scored very favourably for ease of copying, currency, space requirements, 24/7 accessibility, convenience and ease of navigation. However e-books scored poorly compared to print for ease of reading, ease of marking a place and ease of annotation. Regarding use of library print titles, data from all respondents indicated that women (42%) were more likely to be regular users of print than men (35%). Print book discovery behaviour is complex, and age, gender and subject area all influenced book discovery preferences. Analysis of data regarding satisfaction with UCL’s current provision of print library books showed that 41% rated this service as “excellent” or “good,” but further analysis by gender, age and subject area revealed pockets of low satisfaction which warrant further attention. Students were much more aware of e-book availability through the UCL library than academic and research staff, with differences in awareness also displayed between different faculties. The library’s Web site and catalogue were the main channels for e-book awareness, with respondents themselves suggesting the library Web site and e-mail user guides as the most effective e-book awareness mechanisms. Conclusion – This study reveals a significant level of interest in and use of e-books in one academic community, but with differences determined by age, gender, academic sub-group and subject area. It builds on the findings of previous studies of e-book usage and indicates key areas for further study. These include whether real-life information behaviour correlates with the self-reporting of respondents, and the intersection of gender and self-reported information behaviour. This information, plus the patterns of book discovery behaviour emerging from this study, will be of interest to publishers, booksellers and libraries.

Purpose – This paper aims to observe, measure and record comparative cognitive processes in print and online to explain the differences, if any, in the readers’ information-gathering processes and their subsequent comprehension and retention of information. It also examined the strategies that readers adopt that differ from print when reading online. Standardized reading comprehension scores were also collected. The results indicated that the participants demonstrated functional equivalency in both media, but they had a preference for print. The linear individualistic mentality learned through print gave the study group participants the skills to successfully navigate through the dense web of information that constitutes the Internet. Story presentation and hierarchy, key elements of the print design process, are less evident or absent online. As a consequence, as previous research has demonstrated, online readers are more poorly informed than print readers – but not in this case. The research from this study demonstrates that when the authors of the print media are those who also control the integrity of online content, print and Web readers are equally well-informed. Design/methodology/approach – Coded texts from The Guardian Newspaper, The Economist and The New Yorker were used in a media lab to measure the study group’s ability to read and retrieve information from the publications’ print and Web editions. They were scored on how well they retrieved the core information in the articles from both media. Focus-group sessions probed for information about reading in print and online at the end of the reading sessions. This gave valuable insight into the coping strategies that the participants used when engaging with online texts. There were two sessions, each of three hours, and the participants were university students. Findings – The study results show that the group participants were functionally equivalent in both print and online reading. However, they had a profound distrust for online content in general, which they found to be inaccurate and unstable. Web sites, they conclude, never achieve “fixity”. When reading online, the study group scrolls through the text to retrieve facts and then goes to a print source to verify the accuracy of the content. They do not engage with the content online as they do with print. While acknowledging that the publications in the study were reputable and of a high quality, the group still found scrolling through the Web sites tedious. The printed page was to the study group, a cultural object. Research limitations/implications – This was a small study with 11 participants in a controlled environment on two evenings, each lasting three hours. While the readings were intense, the researchers saw no evidence of fatigue. The group were very vocal during the focus-group sessions and gave valuable insights into the reading process. The stories were exactly the same in both media, were well-written and edited. Typographic cues that give the reader priorities when engaging with the texts were transferred from the print to the online editions. HTML texts to this group are an impediment to the reading process, and the amount of texts require too much time to read. A larger study with a more diverse readership reading more general news is required to verify the findings. This is being planned. As one from the study group stated “I grew up with print but younger people do not have the benefits of print”. Practical implications – Typography provides a language with visual form and through that form, conveys the meaning of a text. The print reader decodes what she reads on the printed page, allowing her to quickly absorb and parse large amount of text, discarding redundant content. The question now becomes which print-reading operations are being transferred to the process of extracting relevant facts. Five centuries of continuous improvement of print communications have yet to be successfully transferred to the Internet. The visual aspects of print, the color advertisement, the photograph and elements that aided the print reader’s navigation are an intrusion on the Web. A new form of navigation, one that is more elegant and intuitive than the present, is required. Social implications – The social implications of reading are a fundamental characteristic of any society. The codex provided the model for the book, the newspaper and the magazine. These became and still are trusted sources of information. When the study group gets a Twitter or Facebook prompt on a breaking news story, they check a trusted broadcasting source for confirmation of its accuracy. If the findings of this study are confirmed in subsequent research studies on the process of reading online, it will have profound implications for the industry. Publishing to be successful requires the reader to engage with and respond to a message. There is strong evidence that this is not the case with what the advertising industry would consider an important core audience, the Internet “reader”. Originality/value – As a newspaper and magazine designer and teacher, the author been increasingly concerned with the transfer of information from the printed page to the computer screen. Many studies have been conducted on aspects of reading and designing for online reading. They are very often inaccurate and as such inconclusive. Reading is complex and measuring it difficult. The author conducted this study as both a designer and from an academic perspective. It is hoped that it encourages a robust debate.

Over the years, Encyclopaedia Britannica has undergone a number of revisions and has been provided in a number of formats other than print. The different electronic formats include a CD‐ROM version, a subscription online version, a free online version that was recently changed to a subscription version, and a DVD‐ROM version. The purpose of this study was to evaluate the usability and effectiveness of the different electronic versions of the Encyclopaedia Britannica. The objectives of this study were to find out if one of the electronic versions of the Encyclopaedia Britannica is easier to use than the others, to see if the users are satisfied with the information that they retrieved from each version, and to see if the users retrieve the same information from each version. Over one third (six) of 15 participants thought that britannica.com was the easiest to use. The main reason mentioned was the set‐up of the initial results screen. Most of the participants felt that all of the databases answered the searches sufficiently and nine participants felt that britannica.com answered the searches the best. The main reason mentioned was the variety of information sources provided on the search results page (Encyclopaedia Britannica articles, magazine articles, Web sites, and books). Seven of the participants were satisfied with using all of the databases.

PurposePublic libraries and public service broadcasters are threatened by political developments in the UK and USA. They are targets in a divisive culture war waged by ideological organisations that disseminate misleading and false information about social and political matters on line, on screen and in print. The purpose of this paper is to alert information professionals to this issue and suggests that, although they should not engage in this war, they must be prepared to use their professional expertise to identify and correct unreliable material. Further, they should cooperate with other true information organisations to expose the fallacious sources that endanger democracy.Design/methodology/approachThe authors analysed material from academic texts and papers, professional journals, serious contemporary journalism, political manifestoes, Internet blogs and items from the BBC sound archive to illustrate the history, size and nature of the problem and to suggest how it might be dealt with. This documentary analysis was based on the belief that information professionals are not the only people examining and concerned about this issue. It therefore included material from a wide range of other disciplines, including psychology, medicine and politics.FindingsThere is evidence that populist movements from the political right dislike information organisations and have historically, through misinformation and misrepresentation, persuaded working class citizens that they are being exploited by an elite. Public libraries and the BBC are highly trusted organisations, but much of the British public goes to sources it trusts least, such as tabloid newspapers, for information on politics and society. Librarians and BBC broadcasters demonstrated their value during the COVID-19 pandemic, but they need to engage with other professional groups to fully understand what is happening and counteract the threats it presents to our democracy.Originality/valueThe paper deals with a significant current issue that needs to be considered urgently by practitioners, academics and policy makers. It includes practical examples and suggestions demonstrating how information workers have and can help their users identify and use trusted and accurate information sources and perhaps be made aware of editorial bias.

Purpose The purpose of this paper is to examine the representation of women in Canadian broadcast news coverage, exploring the notion of substantive representation as it relates to gender, leadership and framing. Design/methodology/approach Using computer-aided text analysis software, the authors analyzed the frequency of women appearing in on-air roles, the way in which they are framed, as well as technical and expressive details, such as how they are featured. In total, the authors analyzed representation of 2,031 individuals in the four suppertime local news broadcasts from 6 p.m. to 7 p.m. Framed in an ecological model of complex social change, this paper focuses on understanding how women are presented in Canadian broadcast media. Findings This study finds that women are under-represented in Canadian broadcast media. Furthermore, it finds that women are less likely to be framed as leaders or experts and are less likely to hold news host or anchor positions. For all major news broadcasters analyzed, women are less likely to be portrayed positively or in leadership/expert positions and are more often represented as victims. They are less likely to appear on screen and are more likely to be referred to off-screen, paraphrased and cited rather than speaking for themselves. Research limitations/implications By framing this study in an (critical) ecological, this study moved beyond required descriptive benchmarking to examine the degree of substantive representation of women. However, the sample of the study is only a snapshot of Canada’s largest city, and, therefore, more research involving further a comparative analysis of cities, a variety of print sources and online media outlets is needed. Future research might include more qualitative analysis of the representation, the type of representation and the factors affecting levels of representation. For example, such research might explore the practices in broadcast organizations, the way in which stories are framed and how guests selected. Also of interest is the relationship between women’s representation at the decision-making table, as an input, and the representation of women in on-air roles, as an outcome. Practical implications The implications of this article are important for understanding the complex factors affecting female leadership across sectors, particularly, the Canadian broadcast industry, the barriers they face and the strategies that may lead to their advancement. Originality/value This study moved beyond descriptive benchmarking to examine the degree of substantive representation of women by coding the frames, roles and means of quotation experienced by women on broadcast news.

A Review of: Hobbs, K., & Klare, D. (2016). Are we there yet?: A longitudinal look at e-books through students’ eyes. Journal of Electronic Resources Librarianship, 28(1), 9-24. http://dx.doi.org/10.1080/1941126X.2016.1130451 Abstract Objective – To determine undergraduate students’ opinions of, use of, and facility with e-books. Design – A qualitative study that incorporated annual interview and usability sessions over a period of four years. The protocol was informed by interview techniques used in prior studies at Wesleyan University. To supplement the body of qualitative data, the 2014 Measuring Information Service Outcomes (MISO) survey was distributed; the researchers built five campus-specific e-book questions into the survey. Setting – A small university in the Northeastern United States of America. Subjects – 28 undergraduate students (7 per year) who attended summer session between the years of 2011-2014 recruited for interview and usability sessions; 700 full-time undergraduate students recruited for the 2014 MISO survey. Methods – The method was designed by a library consortium in the Northeastern United States of America. The study itself was conducted by two librarians based at the single university. To recruit students for interview and usability sessions, librarians sent invitations via email to a random list of students enrolled in the university’s summer sessions. Recruitment for the 2014 MISO survey was also conducted via email; the survey was sent to a stratified, random sample of undergraduate students in February 2014. Interview sessions were structured around five open-ended questions that examined students’ familiarity with e-books and whether the format supports academic work. These sessions were followed by the students’ evaluation of specific book titles available on MyiLibrary and ebrary, platforms accessible to all libraries in the CTW Consortium. Participants were asked to locate e-books on given topics, answer two research questions using preselected e-books, explain their research process using the above mentioned platforms, and comment on the overall usability experience. Instead of taking notes during interview and usability sessions, the researchers recorded interviews and captured screen activity. Following sessions, they watched recordings, took notes independently, and compared notes to ensure salient points were captured. Due to concerns that a small pool of interview and usability candidates might not capture the overall attitude of students towards e-books, the researchers distributed the 2014 MISO survey between the third and fourth interview years. Five additional campus-specific e-book questions were included. The final response rate was 33%. Main Results – The results of the interviews, usability studies, and MISO survey suggest that although students use print and electronic formats for complementary functions, 86% would still select print if they had to choose between the formats. Findings indicate that e-books promote discovery and convenient access to information, but print supports established and successful study habits, such as adding sticky notes to pages or creating annotations in margins. With that being said, most students do not attempt to locate one specific format over another. Rather, their two central concerns are that content is relevant to search terms and the full-text is readily available. Study findings also suggest that students approach content through the lens of a particular assignment. Regardless of format, they want to get in, locate specific information, and move on to the next source. Also, students want all sources – regardless of format – readily at hand and arranged in personal organization systems. PDF files were the preferred electronic format because they best support this research behaviour; content can be arranged in filing systems on personal devices or printed when necessary. Because of these research habits, digital rights management (DRM) restrictions created extreme frustration and were said to impede work. In some cases, students created workarounds for the purpose of accessing information in a usable form. This included visiting file sharing sites like Pirate Bay in order to locate DRM free content. Findings demonstrated a significant increase in student e-book use over the course of four years. However, this trend did not correspond to increased levels of sophistication in e-book use or facility with build-in functions on e-book platforms. The researchers discovered that students create workarounds instead of seeking out menu options that save time in the long run. This behaviour was consistent across the study group regardless of individual levels of experience working with e-books. Students commented that additional features slow down work rather than creating efficiency. For instance, when keyboard shortcuts used to copy and paste text did not function, students preferred to type out a passage rather than spend time searching for copy functions available on the e-book platform. Conclusion – Academic e-books continue to evolve in a fluid and dynamic environment. While the researchers saw improvements over the course of four years (e.g., fewer DRM restrictions) access barriers remain, such as required authentication to access platform content. They also identified areas where training sessions lead by librarians could demonstrate how e-books support student research and learning activities. The researchers also found that user experiences are local in nature and specific to campus cultures and expectations. They concluded that knowledge of local user communities should drive book format selection. Whenever possible, libraries should provide access to multiple formats to support a variety of learning needs and research behaviours.

To ensure that photovoltaics contributes significantly to future world energy production, the cost per watt of producing solar cells needs to be drastically reduced. The use of n-type silicon wafers in conjunction with industrial print technology has the potential to lower the cost per watt of solar cells. The use of n-type silicon is expected to allow the use of cheaper Cz substrates, without a corresponding loss in device efficiency. Printed metallisation is well utilised by the PV industry due to its low cost, yet there are few examples of its application to n-type solar cells. This thesis explores the use of n-type Cz silicon with printed metallisation and diffusion from printed sources in creating industrially applicable solar cell structures. The thesis begins with an overview of existing n-type solar cell structures, previous printed thick film metallisation research and previous research into printed dopant sources. A study of printed thick-film metallisation for n-type solar cells is then presented, which details the fabrication of boron doped p-type emitters followed by a survey of thick film Ag, Al, and Ag/Al inks for making contact to a p-emitter layer. Drawbacks of the various inks include high contact resistance, low metal conductivity or both. A cofire regime for front and rear contacts is established and an optimal emitter selected. A study of printed dopant pastes is presented, with an objective to achieve selective, heavily doped regions under metal contacts without significantly compromising minority carrier lifetime in solar cells. It is found that heavily doped regions are achievable with both boron and phosphorus, but that only phosphorus paste was capable of post-processing lifetime compatible with good efficiencies. The effect of belt furnace processing on n-type silicon wafers is explored, with large losses in implied voltage observed due to contamination of Si wafers from transition metals present in the belt furnace. Due to exposure to chromium in the belt furnace, no significant advantage in using n-type wafers instead of p-type is observed during the belt furnace processing step. Finally, working solar cells with efficiencies up to 16.1% are fabricated utilising knowledge acquired in the earlier chapters. The solar cells are characterised using several new photoluminescence techniques, including photoluminescence with current extraction to measure the quality of metal contacts. The work in this thesis indicates that n-type printed silicon solar cell technology shows potential for good performance at low cost.

Efforts to integrate digital media and information literacy into education are expanding, and some schools have already adopted a whole-school integration approach. There are many pedagogical practices for using audiovisual media in ways that support learning. Media-based activities support literacy development when they strengthen the oral language, inference-making, and reasoning skills that are required for reading comprehension. To learn for a lifetime, the most practical competence is the ability to ask good questions and get answers in order to make wise decisions. The active process of learning to formulate good questions is an essential life skill that school, public, and academic librarians can help to develop in learners and patrons alike. Librarians in school and public libraries have done amazing work in paying attention to stereotypes that exist in children’s literature and books. They can also help students and parents unpack and reflect upon the stereotypes offered in children’s television shows, movies, and games. Close reading of media—the core pedagogy of media literacy—builds a habit of mind that promotes deep awareness of and sensitivity toward the rhetorical purposes of informing, entertaining, and persuading, whether it is print, video, or web-based content. There are challenges to using media effectively in some settings, including restrictive school policies for video use, how to assess credible sources, and choosing the most effective pedagogy for an audience.