Dopant‐Free Polymer HTM‐Based CsPbI2Br Solar Cells with Efficiency Over 17% in Sunlight and 34% in Indoor Light. (26th July 2021)

• Record Type: Journal Article
• Authors: Guo, Zhanglin; Jena, Ajay Kumar; Takei, Izuru; Ikegami, Masashi; Ishii, Ayumi; Numata, Youhei; Shibayama, Naoyuki; Miyasaka, Tsutomu
• Is Part Of: Advanced functional materials. Volume 31:Number 42(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-07-26
• Subjects: CsPbI 2Br -- dopant‐free -- hole‐transporting material -- indoor light -- inorganic perovskite solar cells; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202103614
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: To abate the issue of moisture‐assisted phase transition of CsPbI2 Br, caused by hygroscopic dopants used in the hole‐transporting material (HTM), developing dopant‐free HTMs is necessary. In this work, a new polymer, PDTDT, is developed as a dopant‐free HTM for CsPbI2 Br solar cells, and the device performance and stability are systematically compared with cells employing dopant‐free P3HT. CsPbI2 Br solar cells using PDTDT show an efficiency of 17.36% with V OC of 1.42 V and FF of 81.29%, which is one of the highest values for CsPbI2 Br cells. Moreover, a record‐high efficiency of 34.20% with V OC of 1.14 V under 200 lux indoor light illumination and efficiency of 14.54% (certified efficiency of 13.86%) for a 1 cm 2 device under one sun are accomplished. Importantly, PDTDT shows superior/comparable device stability to P3HT, promising its potential to be an alternative to popular doped Spiro‐OMeTAD and P3HT HTM. Abstract : A new polymer, PDTDT, is developed as hole‐transporting material for CsPbI2 Br solar cells. Using PDTDT, an ultra‐high efficiency of 17.36% with V OC of 1.42 V under one sun and 34.20% with V OC of 1.14 V under 200 lux indoor light are achieved. The PDTDT‐based cells also show superior/comparable stability to dopant‐free P3HT reference.