Investigation of fast processes in semiconductors in the picosecond range

Apparatus based on a YAG laser with a picosecond time resolution was developed for investigating fast processes in semiconductors. Experimental determination of the time dependence of the reflection coefficient made it possible to identify the mechanisms responsible for changes in the carrier density in silicon and in gallium arsenide. In particular, studies were made of the processes of diffusion and linear recombination in single-crystal, polycrystalline, and amorphous samples of silicon and of gallium arsenide.