Organometal halide perovskite based solar cells have emerged as one of the most promising candidates for low-cost and high-efficiency solar cell technologies. Here a Vapor Transfer Method （VTM） is used to fabricate ...Organometal halide perovskite based solar cells have emerged as one of the most promising candidates for low-cost and high-efficiency solar cell technologies. Here a Vapor Transfer Method （VTM） is used to fabricate high quality perovskite thin films in a balanced vacuum capsule. By adjusting the reaction tem- perature, CH_3NHl_3 saturated vapor which then reacts with Pbl_2 films can be controlled and the formation process of CH_3NH_3Pbl_3 perovskite films can be further influenced. Prepared perovskite films which ex- hibit pure phase, smooth surface and high crystallinity are assembled into planar heterojunction inverted solar cells. The whole fabrication process of solar cell devices is organic solution free. Finally, the cham- pion cell achieved power conversion efficiency （PCE） of 13.08% with negligible current-voltage hysteresis under fully open-air conditions. The photovoltaic performance could be further enhanced by optimizing perovskite composition and the device structure.展开更多
Chemical vapor deposition has emerged as the most promising technique for the growth of graphene.However, most reports of this technique use either flammable or explosive gases, which bring safety concerns and extra c...Chemical vapor deposition has emerged as the most promising technique for the growth of graphene.However, most reports of this technique use either flammable or explosive gases, which bring safety concerns and extra costs to manage risk factors. In this article, we demonstrate that continuous monolayer graphene can be synthesized via chemical vapor deposition technique on Cu foils using industrially safe gas mixtures. Important factors, including the appropriate ratio of hydrogen flow and carbon precursor,pressure, and growth time are considered to obtain graphene films. Optical measurements and electrical transport measurements indicate graphene films are with comparable quality to other reports. Such continuous large area graphene can be synthesized under non-flammable and non-explosive conditions, which opens a safe and economical method for mass production of graphene. It is thereby beneficial for integration of graphene into semiconductor electronics.展开更多
以硅酸为硅源、偏铝酸钠为铝源制备硅铝胶,采用气相转移法(VPT)合成了MCM-22分子筛。采用TG-DTA,^(27)AlMAS NMR,^(29)Si MAS NMR等方法对硅铝胶进行了表征,讨论了硅铝胶老化温度对硅铝胶结构及合成MCM-22分子筛的影响。实验结果表明,...以硅酸为硅源、偏铝酸钠为铝源制备硅铝胶,采用气相转移法(VPT)合成了MCM-22分子筛。采用TG-DTA,^(27)AlMAS NMR,^(29)Si MAS NMR等方法对硅铝胶进行了表征,讨论了硅铝胶老化温度对硅铝胶结构及合成MCM-22分子筛的影响。实验结果表明,硅铝胶老化温度的改变影响硅铝胶的含水量和Si的存在形式,导致在合成MCM～22分子筛过程中硅铝胶能够提供的结构单元不一样,从而影响MCM-22分子筛的合成。硅铝胶老化温度为80℃时,硅铝胶的含水量最高,Si的存在形式更具多样性,有利于硅铝胶后期的晶化合成。展开更多
文摘Organometal halide perovskite based solar cells have emerged as one of the most promising candidates for low-cost and high-efficiency solar cell technologies. Here a Vapor Transfer Method （VTM） is used to fabricate high quality perovskite thin films in a balanced vacuum capsule. By adjusting the reaction tem- perature, CH_3NHl_3 saturated vapor which then reacts with Pbl_2 films can be controlled and the formation process of CH_3NH_3Pbl_3 perovskite films can be further influenced. Prepared perovskite films which ex- hibit pure phase, smooth surface and high crystallinity are assembled into planar heterojunction inverted solar cells. The whole fabrication process of solar cell devices is organic solution free. Finally, the cham- pion cell achieved power conversion efficiency （PCE） of 13.08% with negligible current-voltage hysteresis under fully open-air conditions. The photovoltaic performance could be further enhanced by optimizing perovskite composition and the device structure.
文摘Chemical vapor deposition has emerged as the most promising technique for the growth of graphene.However, most reports of this technique use either flammable or explosive gases, which bring safety concerns and extra costs to manage risk factors. In this article, we demonstrate that continuous monolayer graphene can be synthesized via chemical vapor deposition technique on Cu foils using industrially safe gas mixtures. Important factors, including the appropriate ratio of hydrogen flow and carbon precursor,pressure, and growth time are considered to obtain graphene films. Optical measurements and electrical transport measurements indicate graphene films are with comparable quality to other reports. Such continuous large area graphene can be synthesized under non-flammable and non-explosive conditions, which opens a safe and economical method for mass production of graphene. It is thereby beneficial for integration of graphene into semiconductor electronics.
文摘以硅酸为硅源、偏铝酸钠为铝源制备硅铝胶,采用气相转移法(VPT)合成了MCM-22分子筛。采用TG-DTA,^(27)AlMAS NMR,^(29)Si MAS NMR等方法对硅铝胶进行了表征,讨论了硅铝胶老化温度对硅铝胶结构及合成MCM-22分子筛的影响。实验结果表明,硅铝胶老化温度的改变影响硅铝胶的含水量和Si的存在形式,导致在合成MCM～22分子筛过程中硅铝胶能够提供的结构单元不一样,从而影响MCM-22分子筛的合成。硅铝胶老化温度为80℃时,硅铝胶的含水量最高,Si的存在形式更具多样性,有利于硅铝胶后期的晶化合成。
