A Universal Method of Perovskite Surface Passivation for CsPbX3 Solar Cells with VOC over 90% of the S‐Q limit. (21st August 2022)

• Record Type: Journal Article
• Authors: Guo, Zhanglin; Zhao, Shuai; Shibayama, Naoyuki; Kumar Jena, Ajay; Takei, Izuru; Miyasaka, Tsutomu
• Is Part Of: Advanced functional materials. Volume 32:Number 43(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-21
• Subjects: CsPbX 3 -- high VOC -- indoor photovoltaics -- perovskite solar cells -- surface passivation; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202207554
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: In comparison to hybrid perovskite solar cells (PSCs), all‐inorganic CsPbX3 PSCs suffer from larger V OC deficits, leading to inferior efficiency. The perovskite surface defects like iodine vacancy (VI ) are the main sources of nonradiative recombination causing a V OC deficit. Here, 2, 5‐thiophenedicarboxylic acid (TDCA) is used to passivate the surface VI through the strong coordination interaction between the thiophene unit of TDCA and the undercoordinated Pb 2+ of perovskite. TDCA passivation also elevates the perovskite surface valence band position, leading to a better interfacial energy alignment. Consequently, the V OC of CsPbI2.25 Br0.75 PSCs is remarkably improved from 1.36 to 1.43 V (efficiency from 15.55% to 16.72%), reaching 92% (record‐high among CsPbX3 PSCs) of the Shockley–Queisser V OC limit. This method also promotes the V OC of CsPbI1.5 Br1.5 cell from 1.42 to 1.51 V (90% of the limit) and CsPbIBr2 cell from 1.44 to 1.54 V (87% of the limit), demonstrating its universality for CsPbX3 perovskites. Abstract : A universal perovskite surface passivation method using 2, 5‐thiophenedicarboxylic acid is developed, by which the V OC of different CsPbX3 solar cells are highly enhanced, leaving extremely small V OC deficits.