Design rules for minimizing voltage losses in high-efficiency organic solar cells

• Autor: Qian, Deping ; Zheng, Zilong ; Yao, Huifeng ; Tress, Wolfgang ; Hopper, Thomas R ; Chen, Shula ; Li, Sunsun ; Liu, Jing ; Chen, Shangshang ; Zhang, Jiangbin ; Liu, Xiao-Ke ; Gao, Bowei ; Ouyang, Liangqi ; Jin, Yingzhi ; Pozina, Galia ; Buyanova, Irina A ; Chen, Weimin M ; Inganäs, Olle ; Coropceanu, Veaceslav ; Bredas, Jean-Luc ; Yan, He ; Hou, Jianhui ; Zhang, Fengling ; Bakulin, Artem A ; Gao, Feng
• Assuntos: Electroluminescence ; Molecular chains ; Open circuit voltage ; Organic chemistry ; Performance enhancement ; Perovskites ; Photoelectric effect ; Photoelectric emission ; Photoluminescence ; Photovoltaic cells ; Quantum chemistry ; Radiative recombination ; Solar cells
• É parte de: Nature materials, 2018-08, Vol.17 (8), p.703-709
• Notas: ObjectType-Article-1
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• Descrição: The open-circuit voltage of organic solar cells is usually lower than the values achieved in inorganic or perovskite photovoltaic devices with comparable bandgaps. Energy losses during charge separation at the donor-acceptor interface and non-radiative recombination are among the main causes of such voltage losses. Here we combine spectroscopic and quantum-chemistry approaches to identify key rules for minimizing voltage losses: (1) a low energy offset between donor and acceptor molecular states and (2) high photoluminescence yield of the low-gap material in the blend. Following these rules, we present a range of existing and new donor-acceptor systems that combine efficient photocurrent generation with electroluminescence yield up to 0.03%, leading to non-radiative voltage losses as small as 0.21 V. This study provides a rationale to explain and further improve the performance of recently demonstrated high-open-circuit-voltage organic solar cells.
  
• Editor: England: Nature Publishing Group
  
• Idioma: Inglês