scholarly journals Numerical Analysis of the Detailed Balance of Multiple Exciton Generation Solar Cells with Nonradiative Recombination

2020 ◽  
Vol 10 (16) ◽  
pp. 5558
Author(s):  
Jongwon Lee ◽  
Christiana B. Honsberg
Keyword(s):  
Solar Cells ◽  
Surface Defects ◽  
Detailed Balance ◽  
Nonradiative Recombination ◽  
Multiple Exciton Generation ◽  
Current Variation ◽  
The Status ◽  
Light Concentration ◽  
The Impact ◽  
The Ideal

In this study, we analyzed the nonradiative recombination impact of multiple exciton generation solar cells (MEGSCs) with a revised detailed balance (DB) limit. The nonideal quantum yield (QY) of a material depends on the surface defects or the status of the material. Thus, its QY shape deviates from the ideal QY because of carrier losses. We used the ideal reverse saturation current variation in the DB of MEGSCs to explain the impact of nonradiative recombination. We compared ideal and nonideal QYs with the nonradiative recombination into the DB of MEGSCs under one-sun and full-light concentration. Through this research, we seek to develop a strategy to maintain MEGSC performance.

scholarly journals Limiting Efficiencies of Intermediate Band Solar Cells in Tandem Configuration

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6021
Author(s):  
Jongwon Lee
Keyword(s):  
Solar Cells ◽  
Short Circuit ◽  
Detailed Balance ◽  
Spectrum Management ◽  
Open Circuit ◽  
Optimal Performance ◽  
Tandem Solar Cells ◽  
Intermediate Band ◽  
Intermediate Band Solar Cells ◽  
The Impact

It is necessary to devise innovative techniques to design new high-performance tandem solar cells to meet increasing energy needs. In this study, the theoretical efficiency of intermediate band solar cells (IBSCs) was increased by integrating them with tandem solar cells to produce intermediate band tandem solar cells (IBTSCs). The spectral splitting analysis indicated that the efficient absorption of sub-photon energies was necessary to ensure optimal performance of the IBSCs at each junction of the IBTSC. For this calculation, we assumed all absorption of sub-photon energies are unity. In addition, we applied the variation of absorptivity to the detailed balance limit of a double-junction (DJ) IBTSC. Furthermore, we included the impact of series and shunt resistances of a typical DJ IBTSC to investigate the variations in electrical parameters (short circuit current, open circuit voltage). The performance efficiency also depended on the illumination concentration due to the charge carrier transitions at each junction. We analyzed this aspect to determine the overall performance of the IBTSCs. We replaced the IBSC in the bottom junction with a single-junction solar cell to explore the potential of diverse tandem configurations. DJ IBTSCs achieved a limiting efficiency comparable to that of six-junction solar cells, despite the lower number of junctions. It was challenging for these cells to exhibit optimal performance because of the inefficient spectrum management in the bottom junction. It was concluded that full illumination concentration was required to achieve optimal performance in both junctions of the IBTSC.

scholarly journals Multiple exciton generation in quantum dot-based solar cells

Nanophotonics ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 111-126 ◽  
Author(s):  
Heather Goodwin ◽  
Tom C. Jellicoe ◽  
Nathaniel J.L.K. Davis ◽  
Marcus L. Böhm
Keyword(s):  
Solar Cells ◽  
Quantum Dot ◽  
Charge Carrier ◽  
High Energy ◽  
Proof Of Concept ◽  
Photovoltaic Devices ◽  
Multiple Exciton Generation ◽  
Carrier Multiplication ◽  
Quantum Confined ◽  
The Impact

AbstractMultiple exciton generation (MEG) in quantum-confined semiconductors is the process by which multiple bound charge-carrier pairs are generated after absorption of a single high-energy photon. Such charge-carrier multiplication effects have been highlighted as particularly beneficial for solar cells where they have the potential to increase the photocurrent significantly. Indeed, recent research efforts have proved that more than one charge-carrier pair per incident solar photon can be extracted in photovoltaic devices incorporating quantum-confined semiconductors. While these proof-of-concept applications underline the potential of MEG in solar cells, the impact of the carrier multiplication effect on the device performance remains rather low. This review covers recent advancements in the understanding and application of MEG as a photocurrent-enhancing mechanism in quantum dot-based photovoltaics.

Women and Social Justice

1991 ◽  
Vol 8 (2) ◽  
pp. 347-350
Author(s):  
Mohja Kahf
Keyword(s):  
Social Justice ◽  
Empirical Study ◽  
Argument Structure ◽  
Policy Recommendations ◽  
Present Treatment ◽  
The Family ◽  
The Status ◽  
Comprehensive Reform ◽  
The Impact ◽  
The Ideal

The task undertaken in this book, the development of a “third approach”to the issue of women’s oppression superceding both feminism and traditionalism,is much needed and much neglected in the Islamic movement.Specifically, Ahmad analyzes the impact of the introduction of hudud (Islamicpenal code) laws in Pakistan and makes policy recommendations for theirreform. Although his analysis is not limited in usefulness to Pakistan, it islimited, however, by several shortcomings in argument, structure, and language.Ahmad’s strong points emerge in his empirical study of Pakistani familylaw. While he attempts to refute the criticism that the hudud laws discriminateagainst women, he also recognizes that the application of these laws in alegal patchwork fraught with contradictions has not helped women. For example,the Family Laws Ordinance of 1961 requires all marriages to be officiallyreported but, with common and Islamic opinion being contrary, thislaw is frequently neglected. So when the hudud laws of 1979 made adulterypunishable, women living in Islamic but unreported marriages were reportedfor adultery by vengeful ex-husbands. This particular problem would be solved,Ahmad argues, by punishing such men for slander, a neglected aspect ofthe Shari‘ah’s approach to adultery which is to women’s advantage. He arguesfor an end to “this vicious circle of immediacy, adhocism and temporarysolutions” (p. 48) in the application of the Shari‘ah, and for a more creative,comprehensive reform. His use of statistics from Pakistani courts is an attemptto ground his analysis in the living reality of Pakistani women, anattempt which is only infrequently made by Islamist writers on women’s issues,who usually hide behind obscure generalizations about the ideal society.It is also edifying to see an Islamist writer admit that “we should notdoubt the intent and motive of those who talk on these issues and take adifferent position” (p. 11). Too often this debate over the status of womenresults in bitter and useless finger-pointing in which the advocates of changein women’s conditions are labelled “Western,” as if one had to be Westernto see anything exploitative about the present treatment of Muslim women.Unfortunately, Ahmad does not stick to his promise and succumbs to a defensivediatribe against his ideological opponents, calling them ‘‘crypto-colonialists’’and emphasizing their emergence from the upper classes. The same charge ...

Analysis of the combined effect of long-term heat light soaking and KF/NaF post-deposition treatment on the open-circuit voltage loss in CIGS solar cells

2021 ◽  
Author(s):  
Hamidou TANGARA ◽  
Yulu He ◽  
Muhammad Monirul Islam ◽  
Shogo ISHIZUKA ◽  
Takeaki Sakurai
Keyword(s):  
Solar Cells ◽  
High Efficiency ◽  
Potassium Fluoride ◽  
Open Circuit ◽  
Nonradiative Recombination ◽  
Doping Density ◽  
Cigs Solar Cells ◽  
The Impact ◽  
Post Deposition

Abstract Heat light soaking (HLS) has been known to impact the photovoltaic parameters of Cu(In,Ga)Se2 (CIGS) solar cells for a long time. Recently, the focus shifted to the effect of the procedure on alkali fluoride-treated CIGS. Here, we investigate the impact of long-term HLS on the open-circuit (VOC) loss in high-efficiency CIGS with potassium fluoride (KF) and sodium fluoride (NaF) post-deposition treatment (PDT). HLS is shown to increase the net doping density, however, the subsequent improvement of the VOC is lower than expected. Using an analysis based on the SQ theory, we show that HLS reduces the nonradiative recombination rate in the bulk but increases the one at the interface. We present a model to explain the increase of interface recombination. We further demonstrate that a combination of HLS and KF/NaF-PDT is necessary to enhance the positive impacts of HLS and mitigate the detrimental ones leading to high-efficiency CIGS devices (22%).

Strategic Role of Zakat in Multidimensional Quality of Life in Sijunjung, Indonesia

2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal
Keyword(s):  
Quality Of Life ◽  
Positive Impact ◽  
Wealth Distribution ◽  
Absolute Poverty ◽  
Before And After ◽  
The Status ◽  
Being There ◽  
The Impact

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.

Contemporary Qur'anic Studies in Iran and its Relationship with Qur'anic Studies in the West

2012 ◽  
Vol 14 (1) ◽  
pp. 45-72
Author(s):  
Morteza Karimi-Nia
Keyword(s):  
Islamic Law ◽  
Human Sciences ◽  
The West ◽  
Communications Technologies ◽  
Religious Learning ◽  
The Status ◽  
Islamic Republic Of Iran ◽  
Almost All ◽  
The Impact ◽  
The Relationship

The status of tafsīr and Qur'anic studies in the Islamic Republic of Iran has changed significantly during recent decades. The essay provides an overview of the state of Qur'anic studies in Iran today, aiming to examine the extent of the impact of studies by Western scholars on Iranian academic circles during the last three decades and the relationship between them. As in most Islamic countries, the major bulk of academic activity in Iran in this field used to be undertaken by the traditional ʿulamāʾ; however, since the beginning of the twentieth century and the establishment of universities and other academic institutions in the Islamic world, there has been increasing diversity and development. After the Islamic Revolution, many gradual changes in the structure and approach of centres of religious learning and universities have occurred. Contemporary advancements in modern sciences and communications technologies have gradually brought the institutions engaged in the study of human sciences to confront the new context. As a result, the traditional Shīʿī centres of learning, which until 50 years ago devoted themselves exclusively to the study of Islamic law and jurisprudence, today pay attention to the teaching of foreign languages, Qur'anic sciences and exegesis, including Western studies about the Qur'an, to a certain extent, and recognise the importance of almost all of the human sciences of the West.

Euratom and Brexit: Could the United Kingdom Maintain One Foot in the European Union? Current Scenarios and Future Prospects of British withdrawal from the EAEC

2018 ◽  
Vol 18 (2) ◽  
pp. 134-151
Author(s):  
Andrea Circolo ◽  
Ondrej Hamuľák
Keyword(s):  
European Union ◽  
United Kingdom ◽  
Independent Solution ◽  
Legal Regulation ◽  
The European Union ◽  
The United Kingdom ◽  
The Status ◽  
Long Time ◽  
Energy Community ◽  
The Impact

Abstract The paper focuses on the very topical issue of conclusion of the membership of the State, namely the United Kingdom, in European integration structures. The ques­tion of termination of membership in European Communities and European Union has not been tackled for a long time in the sources of European law. With the adop­tion of the Treaty of Lisbon (2009), the institute of 'unilateral' withdrawal was intro­duced. It´s worth to say that exit clause was intended as symbolic in its nature, in fact underlining the status of Member States as sovereign entities. That is why this institute is very general and the legal regulation of the exercise of withdrawal contains many gaps. One of them is a question of absolute or relative nature of exiting from integration structures. Today’s “exit clause” (Art. 50 of Treaty on European Union) regulates only the termination of membership in the European Union and is silent on the impact of such a step on membership in the European Atomic Energy Community. The presented paper offers an analysis of different variations of the interpretation and solution of the problem. It´s based on the independent solution thesis and therefore rejects an automa­tism approach. The paper and topic is important and original especially because in the multitude of scholarly writings devoted to Brexit questions, vast majority of them deals with institutional questions, the interpretation of Art. 50 of Treaty on European Union; the constitutional matters at national UK level; future relation between EU and UK and political bargaining behind such as all that. The question of impact on withdrawal on Euratom membership is somehow underrepresented. Present paper attempts to fill this gap and accelerate the scholarly debate on this matter globally, because all consequences of Brexit already have and will definitely give rise to more world-wide effects.

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