FA-Cs mixed-cation perovskite has been reported as a promising candidate for obtaining highly efficient and stable photovoltaic devices.Phenylethylamine iodide(PEAI)post-treatment is a widely used and effective method...FA-Cs mixed-cation perovskite has been reported as a promising candidate for obtaining highly efficient and stable photovoltaic devices.Phenylethylamine iodide(PEAI)post-treatment is a widely used and effective method for surface passivation of FA-Cs perovskite layer in devices.However,it is still controversial whether the PEAI post-treatment would form two-dimensional(2D)perovskite PEA_(2)PbI_(4) capping layer or just result in PEA+terminated surface.Here in this work,the function of PEAI post-treatment on FA-Cs mixed-cation perovskite FA_(1-x)Cs_(x)PbI_(3)(x=0.1–0.9)with varied Cs contents is elucidated.With increased Cs content,the FA-Cs perovskite shows higher resistance to the cation exchange between FA+and PEA+.This Cs-content-dependent cation exchange results in the different PEAI reaction preferences with FA-Cs mixed-cation perovskites.Furthermore,higher Cs content with stronger resistance to cation exchange reaction leads to a wider processing window for post-treatment and defect passivation,which is beneficial for the fabrication of large-scale photovoltaic devices.展开更多
Halide perovskite single crystals(SCs)have attracted much attention for their application in high-performance x-ray detectors owing to their desirable properties,including low defect density,high mobility–lifetime pr...Halide perovskite single crystals(SCs)have attracted much attention for their application in high-performance x-ray detectors owing to their desirable properties,including low defect density,high mobility–lifetime product(μτ),and long carrier diffusion length.However,suppressing the inherent defects in perovskites and overcoming the ion migration primarily caused by these defects remains a challenge.This study proposes a facile process for dipping Cs0.05FA0.9MA0.05PbI3 SCs synthesized by a solution-based inverse temperature crystallization method into a 2-phenylethylammonium iodide(PEAI)solution to reduce the number of defects,inhibit ion migration,and increase x-ray sensitivity.Compared to conventional spin coating,this simple dipping process forms a two-dimensional PEA2PbI4 layer on all SC surfaces without further treatment,effectively passivating all surfaces of the inherently defective SCs and minimizing ion migration.As a result,the PEAI-treated perovskite SC-based x-ray detector achieves a record x-ray sensitivity of 1.3×10^(5)μC Gyair^(-1) cm^(-2) with a bias voltage of 30 V at realistic clinical dose rates of 1–5 mGy s^(-1)(peak potential of 110 kVp),which is 6 times more sensitive than an untreated SC-based detector and 3 orders of magnitude more sensitive than a commercialα-Se-based detector.Furthermore,the PEAI-treatedperovskite SC-based x-ray detector exhibits a low detection limit(73 nGy s^(-1)),improved x-ray response,and clear x-ray images by a scanning method,highlighting the effectiveness of the PEAI dipping approach for fabricating next-generation x-ray detectors.展开更多
基金supported by the National Key Research and Development Program of China(2017YFE0127100)the National Natural Science Foundation of China(NSFC,Grant 22025505)+1 种基金the Program of Shanghai Academic Technology Research Leader(Grant 20XD1422200)the Key Laboratory of Resource Chemistry,Ministry of Education(KLRC_ME2003)。
文摘FA-Cs mixed-cation perovskite has been reported as a promising candidate for obtaining highly efficient and stable photovoltaic devices.Phenylethylamine iodide(PEAI)post-treatment is a widely used and effective method for surface passivation of FA-Cs perovskite layer in devices.However,it is still controversial whether the PEAI post-treatment would form two-dimensional(2D)perovskite PEA_(2)PbI_(4) capping layer or just result in PEA+terminated surface.Here in this work,the function of PEAI post-treatment on FA-Cs mixed-cation perovskite FA_(1-x)Cs_(x)PbI_(3)(x=0.1–0.9)with varied Cs contents is elucidated.With increased Cs content,the FA-Cs perovskite shows higher resistance to the cation exchange between FA+and PEA+.This Cs-content-dependent cation exchange results in the different PEAI reaction preferences with FA-Cs mixed-cation perovskites.Furthermore,higher Cs content with stronger resistance to cation exchange reaction leads to a wider processing window for post-treatment and defect passivation,which is beneficial for the fabrication of large-scale photovoltaic devices.
基金Agency for Defense Development,Grant/Award Number:UI220006TDDefense Acquisition Program Administration(DAPA),Grant/Award Number:912765601Korea Institute of Energy Technology Evaluation and Planning,Grant/Award Number:RS-2023-00237035。
文摘Halide perovskite single crystals(SCs)have attracted much attention for their application in high-performance x-ray detectors owing to their desirable properties,including low defect density,high mobility–lifetime product(μτ),and long carrier diffusion length.However,suppressing the inherent defects in perovskites and overcoming the ion migration primarily caused by these defects remains a challenge.This study proposes a facile process for dipping Cs0.05FA0.9MA0.05PbI3 SCs synthesized by a solution-based inverse temperature crystallization method into a 2-phenylethylammonium iodide(PEAI)solution to reduce the number of defects,inhibit ion migration,and increase x-ray sensitivity.Compared to conventional spin coating,this simple dipping process forms a two-dimensional PEA2PbI4 layer on all SC surfaces without further treatment,effectively passivating all surfaces of the inherently defective SCs and minimizing ion migration.As a result,the PEAI-treated perovskite SC-based x-ray detector achieves a record x-ray sensitivity of 1.3×10^(5)μC Gyair^(-1) cm^(-2) with a bias voltage of 30 V at realistic clinical dose rates of 1–5 mGy s^(-1)(peak potential of 110 kVp),which is 6 times more sensitive than an untreated SC-based detector and 3 orders of magnitude more sensitive than a commercialα-Se-based detector.Furthermore,the PEAI-treatedperovskite SC-based x-ray detector exhibits a low detection limit(73 nGy s^(-1)),improved x-ray response,and clear x-ray images by a scanning method,highlighting the effectiveness of the PEAI dipping approach for fabricating next-generation x-ray detectors.
