High-Efficiency Indoor Organic Photovoltaics with a Band-Aligned Interlayer

• Published in: Joule Vol. 4; no. 7; pp. 1486 - 1500
• Main Authors: Ma, Lik-Kuen, Chen, Yuzhong, Chow, Philip C.Y., Zhang, Guangye, Huang, Jiachen, Ma, Chao, Zhang, Jianquan, Yin, Hang, Hong Cheung, Andy Man, Wong, Kam Sing, So, Shu Kong, Yan, He
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15.07.2020
• Subjects: electron transport interlayer; ETL; high efficiency OPV; indoor organic solar cell; indoor solar cell; internet of things; IoT; organic solar cell; OSC; polymer solar cells; indoor organic solar cell; electron transport interlayer; indoor solar cell; internet of things; high efficiency OPV; organic solar cell; polymer solar cells; ETL; OSC; IoT
• ISSN: 2542-4351; 2542-4351
• DOI: 10.1016/j.joule.2020.05.010

The emergence of indoor electronic devices for internet of things (IoT) has motivated the scientific community to develop photovoltaic devices that can efficiently convert indoor light into electricity. In this paper, we report high-efficiency non-fullerene organic photovoltaic (OPV) cells with over 30% power conversion efficiency (PCE) under indoor conditions. Our results show that the choice of electron-transporting layer (ETL) is critically important to enable such performance. The use of an ETL (named PDI-NO) with a deep highest occupied molecular orbital (HOMO) level can effectively suppress leakage current and reduce trap-assisted recombination of the devices. Thus, using this ETL, we achieve record PCE of 31% by utilizing a low-band-gap acceptor in the bulk-heterojunction (BHJ) blend. Whereas, in another case, by employing a large-band-gap acceptor, a PCE of 26.7% with over 1V is achieved. Our study paves the way toward high-performance indoor OPV devices for powering IoT electronics. [Display omitted] •The choice of ETL is the key to achieving the high performance of indoor OPV•A deep HOMO ETL can reduce leakage current and trap-assisted recombination•The device with PDI-NO can achieve a record PCE of 31% under 3,000 K LED condition The emergence of indoor electronic devices for internet of things (IoT) has motivated the scientific community to develop photovoltaic devices that can efficiently convert indoor light into electricity. In this work, we report high-efficiency non-fullerene organic photovoltaic (OPV) cells with over 30% power conversion efficiency (PCE) in indoor conditions. Our results show that the choice of electron-transporting layer (ETL) is important to enable such performance. The use of an ETL (named PDI-NO) with a deep highest occupied molecular orbital (HOMO) level can effectively suppress leakage current and reduce trap-assisted recombination of the devices. Thus, using this ETL, we achieve record PCE of 31% by utilizing a low-band-gap acceptor in the bulk-heterojunction (BHJ) blend. Whereas, in another case, by employing a large-band-gap acceptor, a PCE of 26.7% with over 1V is achieved. Our study paves the way toward high-performance indoor OPV devices for powering IoT electronics. The choice of ETLs are critically important to achieve high-performance indoor OPVs. When applying a deeper HOMO ETL named PDI-NO to a bulk-heterojunction (BHJ) based on a low-band-gap acceptor, we achieve a record PCE of 31% under 3,000 K LED. We also show that this ETL can be applied to another BHJ system based on a wide-band-gap PDI acceptor, which also leads to efficient indoor OPV devices with a PCE of 26% and a high open-circuit voltage (Voc) of over 1V.