biostudies-literatureHe RFundamental Research Funds for the Central UniversitiesScience and Technology Development Fund, Macao SARNatural Science Foundation of ChinaUM's Research FundKey Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow UniversityShenzhen-Hong Kong-Macao Science and Technology Innovation ProjectNational Natural Science Foundation of ChinaScience and Technology Program of Sichuan ProvinceNational Key Research and Development Program of ChinaNatural Science Foundation of Jiangsu Provincee2203210https://www.ebi.ac.uk/biostudies/studies/S-EPMC9799022biostudies-literatureUnknown9(36)Surface post-treatment using ammonium halides effectively reduces large open-circuit voltage (V_OC ) losses in bromine-rich wide-bandgap (WBG) perovskite solar cells (PSCs). However, the underlying mechanism still remains unclear and the device efficiency lags largely behind. Here, a facile strategy of precisely tailoring the phase purity of 2D perovskites on top of 3D WBG perovskite and realizing high device efficiency is reported. The transient absorption spectra, cross-sectional confocal photoluminescence mapping, and cross-sectional Kelvin probe force microscopy are combined to demonstrate optimal defect passivation effect and surface electric-field of pure n = 1 2D perovskites formed atop 3D WBG perovskites via low-temperature annealing. As a result, the inverted champion device with 1.77-eV perovskite absorber achieves a high V_OC of 1.284 V and a power conversion efficiency (PCE) of 17.72%, delivering the smallest V_OC deficit of 0.486 V among WBG PSCs with a bandgap higher than 1.75 eV. This enables one to achieve a four-terminal all-perovskite tandem solar cell with a PCE exceeding 25% by combining with a 1.25-eV low-bandgap PSC.Advanced science (Weinheim, Baden-Wurttemberg, Germany)Pure 2D Perovskite Formation by Interfacial Engineering Yields a High Open-Circuit Voltage beyond 1.28 V for 1.77-eV Wide-Bandgap Perovskite Solar Cells.PMC97990222019YFE0120000BK201908250082/2021/A262005188KJS19092020JDJQ0030619350172019KJT0120-2019ZDZX0015FDCT-0044/2020/A12020YFH007962174112YJ20195562175268SGDX2020110309360100MYRG2020-00151-IAPMEYJ202115761904152Yi ZLai HWang CHuang HZou BChen CHe RXing GFu FLuo JWei QCui GLuo YWang WZhao DXiao CRen SfalsePure 2D Perovskite Formation by Interfacial Engineering Yields a High Open-Circuit Voltage beyond 1.28 V for 1.77-eV Wide-Bandgap Perovskite Solar Cells.Surface post-treatment using ammonium halides effectively reduces large open-circuit voltage (V_OC ) losses in bromine-rich wide-bandgap (WBG) perovskite solar cells (PSCs). However, the underlying mechanism still remains unclear and the device efficiency lags largely behind. Here, a facile strategy of precisely tailoring the phase purity of 2D perovskites on top of 3D WBG perovskite and realizing high device efficiency is reported. The transient absorption spectra, cross-sectional confocal photoluminescence mapping, and cross-sectional Kelvin probe force microscopy are combined to demonstrate optimal defect passivation effect and surface electric-field of pure n = 1 2D perovskites formed atop 3D WBG perovskites via low-temperature annealing. As a result, the inverted champion device with 1.77-eV perovskite absorber achieves a high V_OC of 1.284 V and a power conversion efficiency (PCE) of 17.72%, delivering the smallest V_OC deficit of 0.486 V among WBG PSCs with a bandgap higher than 1.75 eV. This enables one to achieve a four-terminal all-perovskite tandem solar cell with a PCE exceeding 25% by combining with a 1.25-eV low-bandgap PSC.2022-01-01T00:00:00Z2022 Dec2025-04-22T04:30:34.948Z2025-04-05T21:00:39.579ZS-EPMC97990223637255110.1002/advs.202203210