Guanidium-assisted crystallization engineering for highly efficient CsPbI3 solar cells. Issue 21 (19th May 2022)

• Record Type: Journal Article
• Authors: Wang, Shuo; Xu, Youkui; Wang, Qian; Zhou, Xufeng; Li, ZhenHua; Wang, Meng; Lei, Yutian; Zhang, Hong; Wang, Haoxu; Jin, Zhiwen
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 21(2022)
• Page Start: 8234
• Page End: 8240
• Publication Date: 2022-05-19
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc01008a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : This work mainly focuses on utilizing GA + to reduce non-radiative recombination in CsPbI3 by inhibiting the formation of iodine vacancies and passivating incompatible iodide, and the champion PCE was demonstrated to be 19.05% with a V OC of 1.14 V. Abstract : Iodine vacancies and uncoordinated iodide ions of CsPbI3 films are mainly responsible for nonradiative recombination. Here, we report a composition-engineering passivation method that through guanidium (GA + ) and I − forms strong hydrogen bonds to passivate iodine vacancies and reduce defects. Both experimental and theoretical results confirmed strong chemical interactions between GA + and uncoordinated I − in the GA x Cs1− x PbI3 bulk or at the grain boundary. Moreover, GA + doping could slow down the crystallization speed of perovskite films during the deposition process. As a result, we observed GA + modified films with much lower defect density, larger grain size, and better carrier extraction and transportation. Upon GA + passivation, the power conversion efficiency (PCE) is boosted from 18.01% to 19.05%, with open-circuit voltage ( V OC ) enhancement from 1.08 V to 1.14 V.