Perovskite solar cells have developed rapidly in the past decades.However,there are large amounts of ionic defects at the surface and grain boundaries of perovskte films which are detrimental to both the efficiency an...Perovskite solar cells have developed rapidly in the past decades.However,there are large amounts of ionic defects at the surface and grain boundaries of perovskte films which are detrimental to both the efficiency and stability of perovskite solar cells.Here,an organic halide salt pyridinium iodide(PyI) is used in cation-anion-mixed perovskite for surface defect passivation.Different from the treatment with Lewis base pyridine(Py) which can only bind to the under-coordinated Pb ions,zwitterion molecule PyI can not only fill negative charged iodine vacancies,but also interact with positive charged defects.Compared with Py treatment,PyI treatment results in smoother surface,less defect densities and nonradiative recombination in perovskite,leading to an improved VOC, negligible J-V hysteresis and stable performance of devices.As a result,the champion PyI-treated planar perovskite solar cell with a high VOC of 1.187 V achieves an efficiency of 21.42%,which is higher than 20.37% of Py-treated device,while the pristine device without any treatment gets an efficiency of 18.83% at the same experiment conditions.展开更多
In this paper, we verify Vogan＇s conjecture on quantization in the representation theory for G = GL（n, C）. Also we get some relationship between the induction of orbits and Howe＇s θ-lifting of unitary representat...In this paper, we verify Vogan＇s conjecture on quantization in the representation theory for G = GL（n, C）. Also we get some relationship between the induction of orbits and Howe＇s θ-lifting of unitary representations展开更多
基金the joint financial support from the National Natural Science Foundation of China (No. U1705256, 51972123, 21771066 and 61804058)the Cultivation Program for Postgraduate in Scientific Research Innovation Ability of Huaqiao University (No. 18014087027)。
文摘Perovskite solar cells have developed rapidly in the past decades.However,there are large amounts of ionic defects at the surface and grain boundaries of perovskte films which are detrimental to both the efficiency and stability of perovskite solar cells.Here,an organic halide salt pyridinium iodide(PyI) is used in cation-anion-mixed perovskite for surface defect passivation.Different from the treatment with Lewis base pyridine(Py) which can only bind to the under-coordinated Pb ions,zwitterion molecule PyI can not only fill negative charged iodine vacancies,but also interact with positive charged defects.Compared with Py treatment,PyI treatment results in smoother surface,less defect densities and nonradiative recombination in perovskite,leading to an improved VOC, negligible J-V hysteresis and stable performance of devices.As a result,the champion PyI-treated planar perovskite solar cell with a high VOC of 1.187 V achieves an efficiency of 21.42%,which is higher than 20.37% of Py-treated device,while the pristine device without any treatment gets an efficiency of 18.83% at the same experiment conditions.
基金The author would like to thank Professor Jing-Song Huang and Professor Fu-Hai Zhu for very helpful suggestion. This work was supported in part by the National Natural Science Foundation of China （Grant No. 10971103）.
文摘In this paper, we verify Vogan＇s conjecture on quantization in the representation theory for G = GL（n, C）. Also we get some relationship between the induction of orbits and Howe＇s θ-lifting of unitary representations
