Photoelectric properties of polycrystalline films grown on alternative substrates
The photoelectric and electrical properties and structure of polycrystalline films grown on and GaAs substrates are studied. The films obtained, having a high photosensitivity in particular at room temperature, show promise for infrared optoelectronics. A comprehensive investigation of the photoconductivity spectra, lux-ampere characteristics and temperature dependences of the photoelectric and electrical characteristics have established the significant influence of electrically active grain boundaries on the photoelectric parameters. It has been found that lux-ampere characteristics of films have a nonconventional pattern which is manifested in an increase of slope at high rates of laser excitation. The role of potential barriers in the generation-recombination processes in polycrystalline films is discussed in the context of a model of an inhomogeneous semiconductor whose energy bands are modulated by a random potential.