Light-induced effects on doped- and undoped-hydrogenated amorphous silicon

This article presents the light-induced effects on the electrical and optical properties of undoped- and doped-hydrogenated amorphous silicon films. The changes in the conductivities and the activation energies of various types of a-Si:H films due to the prolonged exposure to light have been characterized as a function of deposition conditions and illumination periods. We have also analyzed the variations of microstructure of a-Si:H film such as silicon–hydrogen bondings in the rocking and stretching modes utilizing infrared spectroscopy. From the experimental results, it is clear that doping effects must be crucial to the degradations of the fundamental properties of a-Si:H due to light-induced effects.