Interfacial Engineering of Wide‐Bandgap Perovskites for Efficient Perovskite/CZTSSe Tandem Solar Cells. (4th October 2021)

• Record Type: Journal Article
• Authors: Wang, Deng; Guo, Hongling; Wu, Xin; Deng, Xiang; Li, Fengzhu; Li, Zhen; Lin, Francis; Zhu, Zonglong; Zhang, Yi; Xu, Baomin; Jen, Alex K.‐Y.
• Is Part Of: Advanced functional materials. Volume 32:Number 2(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-10-04
• Subjects: interfacial engineering -- non‐radiative recombination -- quasi‐2D perovskite interfaces -- VOC deficit -- wide‐bandgap perovskite solar cells; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202107359
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Wide‐bandgap perovskites have attracted substantial attention due to their important role in serving as a top absorber in tandem solar cells (TSCs). However, wide‐bandgap perovskite solar cells (PVSCs) typically suffer from severe non‐radiative recombination loss and therefore exhibit high open‐circuit voltage ( V OC ) deficits. To address these issues, a 2D octyl‐diammonium lead iodide interlayer is adopted onto the hole‐transporting layer to induce the formation of an ultrathin quasi‐2D perovskite that is close to the hole‐selective interface. This approach not only accelerates hole transfer and retards hole accumulation but also reduces the trap density in the perovskite layer on top, thereby efficiently suppresses non‐radiative recombination pathways. Consequently, the champion wide‐bandgap device (≈1.66 eV) exhibits a power conversion efficiency (PCE) of 21.05% with a V OC of 1.23 V, where the V OC deficit of 0.43 V is among the lowest values for inverted wide‐bandgap PVSCs. Moreover, by stacking a semi‐transparent perovskite top cell on a 1.1 eV Cu2 ZnSn(S, Se)4 (CZTSSe) bottom cell, a 22.27% PCE was achieved on a perovskite/CZTSSe four‐terminal tandem solar cell, paving the way for all‐solution‐processed, low‐cost, and efficient TSCs with mitigated energy loss in the wide‐bandgap top cells. Abstract : This study introduces an octyl‐diammonium lead iodide (ODAPbI4 ) interlayer onto the hole‐transporting layer, which significantly reduces nonradiative recombination of wide‐bandgap perovskite devices, enhancing the efficiency of wide‐bandgap devices beyond 21%. By coupling a semitransparent device with a Cu2 ZnSn(S, Se)4 (CZTSSe) cell, a four terminal perovskite/CZTSSe tandem cell with a power conversion efficiency of 22.27% is achieved.