![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() by Staff Writers Nanjing, China (SPX) Sep 03, 2021
The power conversion efficiency (PCE) of single-junction perovskite solar cells (PSCs) has increased remarkably from 3.8% to 25.2% in just a decade. As the rapid development of PCE has been approaching the limit of its theoretical efficiency, fabricating tandem solar cells by combining subcells with different bandgaps offers an avenue to go beyond the Shockley-Queisser limits of single-junction solar cells. The tandem devices utilize different parts of the solar spectra using subcells with different bandgaps to reduce the thermal loss of photo-generated carriers. Due to the tunable bandgap, high absorption coefficient and low fabrication cost, metal halide perovskites are promising candidates for tandem devices. However, the efficiency of perovskite-based tandem solar cells is largely limited by wide-bandgap top-cells which typically possess a large open-circuit voltage (VOC) loss. The severe nonradiative charge recombination at the interface between perovskite and hole transport layer (HTL) is a key factor leading to the large VOC loss. Recently, research group of Prof. Hairen Tan from Nanjing University has used the cross-linked organic small molecule VNPB as the HTL for wide-bandgap perovskite solar cells. A VOC increase of nearly 50 mV was successfully obtained for wide-bandgap solar cells with bandgaps of 1.6 eV, 1.7 eV and 1.8 eV. Compared with the control device using PTAA polymeric HTL, the perovskite films deposited on VNPB have larger grain size and better crystallinity. VNPB enables faster charge extraction and reduces defect density at the HTL/perovskite interface. Density functional theory (DFT) calculation shows that the closer contact between VNPB and perovskite increases the defect formation energy and decreases the defect density, thus effectively reducing the non-radiative recombination of carriers. Finally, the PCEs of perovskite/perovskite and perovskite/silicon tandem solar cells using VNPB as HTL reach 24.9% and 25.4%, respectively. This work shows that cross-linkable small molecules are promising for high-efficiency and cost-effective perovskite tandem photovoltaic devices.
Research Report: "Cross-linked hole transport layers for high efficiency perovskite tandem solar cells"
![]() ![]() WTO rules for US in Chinese solar tariff dispute Washington (AFP) Sept 2, 2021 The World Trade Organization (WTO) on Thursday ruled in favor of the United States in a dispute with China over tariffs on solar panels Washington imposed as part of the countries' trade war. Former US president Donald Trump approved steep tariffs on solar panel imports in January 2018 to protect US producers, triggering an outcry from China and South Korea, and even protests from the American solar industry. Beijing requested the WTO set up a dispute panel to judge whether the tariffs violated ... read more
![]() |
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |