Dopant‐Free Polymer Hole Transport Materials for Highly Stable and Efficient CsPbI3 Perovskite Solar Cells. Issue 11 (21st December 2022)

• Record Type: Journal Article
• Authors: Zhang, Zelong; Fu, Jianfei; Chen, Qiaoyun; Zhang, Jiajia; Huang, Zhezhi; Cao, Ji; Ji, Wenxi; Zhang, Longgui; Wang, Ailian; Zhou, Yi; Dong, Bin; Song, Bo
• Is Part Of: Small. Volume 19:Issue 11(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-21
• Subjects: CsPbI 3 -- dopant‐free -- hole transport layers -- perovskite solar cells -- PM6; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202206952
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: All‐inorganic perovskite CsPbI3 contains no volatile organic components and is a thermally stable photoactive material for wide‐bandgap perovskite solar cells (PSCs); however, CsPbI3 readily undergoes undesirable phase transitions due to the hygroscopic nature of the ionic dopants used in commonly used hole transport materials. In the current study, the popular donor material PM6 in organic solar cells is used as a hole transport layer (HTL). The benzodithiophene‐based backbone‐conjugated polymer requires no dopant and leads to a higher power conversion efficiency (PCE) than 2, 2′, 7, 7′‐tetrakis[N, N‐di(4‐methoxyphenyl)amino]‐9, 9′‐spirobifluorene (Spiro‐OMeTAD). Moreover, PM6 also shows priorities in hole mobility, hydrophobicity, cascade energy level alignment, and even defect passivation of perovskite films. With PM6 as the dopant‐free HTL, the PSCs achieve a champion PCE of 18.27% with a competitive fill factor of 82.8%. Notably, the present PCE is based on the dopant‐free HTL in CsPbI3 PSCs reported thus far. The PSCs with PM6 as the HTL retain over 90% of the initial PCE stored in a glovebox filled with N2 for 3000 h. In contrast, the PSCs with Spiro‐OMeTAD as the HTL maintain ≈80% of the initial PCE under the same conditions. Abstract : The popular donor used in organic solar cells PM6 is found an excellent dopant‐free hole transport material in CsPbI3 perovskite solar cells. As an alternative candidate for 2, 2′, 7, 7′‐tetrakis[N, N‐di(4‐methoxyphenyl)amino]‐9, 9′‐spirobifluorene, PM6's relative hydrophobic nature and interaction with perovskite through thiophene and fluorine functional groups can protect perovskite and improve the quality, thus leading to enhanced efficiency and stability of the corresponding devices.