Efficient Organic Solar Cells with Extremely High Open‐Circuit Voltages and Low Voltage Losses by Suppressing Nonradiative Recombination Losses |
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| Authors: | Xi Liu Xiaoyan Du Junyi Wang Chunhui Duan Xiaofeng Tang Thomas Heumueller Guogang Liu Yan Li Zhaohui Wang Jing Wang Feng Liu Ning Li Christoph J. Brabec Fei Huang Yong Cao |
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| Affiliation: | 1. Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, P. R. China;2. Institute of Materials for Electronics and Energy Technology (i‐MEET), Friedrich‐Alexander‐Universit?t Erlangen‐Nürnberg, Erlangen, Germany;3. Institute of Chemistry, Chinese Academy of Sciences, Beijing, P. R. China;4. Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, P. R. China;5. Bavarian Center for Applied Energy Research (ZAE Bayern), Erlangen, Germany |
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| Abstract: | One of the most important factors that limits the efficiencies of bulk‐heterojunction organic solar cells (OSCs) is the modest open‐circuit voltage (Voc) due to their large voltage loss (Vloss) caused by significant nonradiative recombination loss. To boost the performance of OSCs toward their theoretical limit, developing high‐performance donor: acceptor systems featuring low Vloss with suppressed nonradiative recombination losses (<0.30 V) is desired. Herein, high performance OSCs based on a polymer donor benzodithiophene‐difluorobenzoxadiazole‐2‐decyltetradecyl (BDT‐ffBX‐DT) and perylenediimide‐based acceptors (PDI dimer with spirofluorene linker (SFPDI), PDI4, and PDI6) are reported which offer a high power conversion efficiency (PCE) of 7.5%, 56% external quantum efficiency associated with very high Voc (>1.10 V) and low Vloss (<0.60 V). A high Voc up to 1.23 V is achieved, which is among the highest values reported for OSCs with a PCE beyond 6%, to date. These attractive results are benefit from the suppressed nonradiative recombination voltage loss, which is as low as 0.20 V. This value is the lowest value for OSCs so far and is comparable to high performance crystalline silicon and perovskite solar cells. These results show that OSCs have the potential to achieve comparable Voc and voltage loss as inorganic photovoltaic technologies. |
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| Keywords: | nonfullerene acceptors nonradiative recombination losses open‐circuit voltages organic solar cells voltage losses |
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