Lead iodide（PbI_2） films have been prepared by the electron beam evaporation technique,and their photoconductive response to visible light was investigated under different deposition and illumination conditions.It i...Lead iodide（PbI_2） films have been prepared by the electron beam evaporation technique,and their photoconductive response to visible light was investigated under different deposition and illumination conditions.It is found that the films＇ photoconductive response speed increases and the relative sensitivity decreases with the increase of substrate temperature due to the opposite requests for photo-carrier lifetime.Further,appropriately increasing the film＇s thickness and rising substrate temperature simultaneously can effectively balance the opposite demands.Under optimized conditions of a substrate temperature of 200℃,a source-substrate distance of 30 cm and a deposition time of 10 min,the prepared films exhibit the best response properties.In addition,the response to illumination with different wavelengths was also measured,revealing that the decline of response performance with increasing wavelength is due to the lower photon energy of incident light.展开更多
基金Project supported by the National Natural Science Foundation of China(No.50902012)the Natural Science Foundation of Sichuan Province,China(No.2009JY0087).
文摘Lead iodide（PbI_2） films have been prepared by the electron beam evaporation technique,and their photoconductive response to visible light was investigated under different deposition and illumination conditions.It is found that the films＇ photoconductive response speed increases and the relative sensitivity decreases with the increase of substrate temperature due to the opposite requests for photo-carrier lifetime.Further,appropriately increasing the film＇s thickness and rising substrate temperature simultaneously can effectively balance the opposite demands.Under optimized conditions of a substrate temperature of 200℃,a source-substrate distance of 30 cm and a deposition time of 10 min,the prepared films exhibit the best response properties.In addition,the response to illumination with different wavelengths was also measured,revealing that the decline of response performance with increasing wavelength is due to the lower photon energy of incident light.
