MEASUREMENT OF SURFACE AND INTERFACE RECOMBINATION VELOCITIES IN GaAs-GaP p-p HETEROJUNCTIONS.
In order to make an efficient transmission photocathode of III-V semiconductors, a heterostructure composed of two different single crystal films is required. The material with the larger bandgap serves as a window, the other as a cathode. The lattice mismatch at the interface often degrades electrical performance. Two important parameters, the interface recombination velocity and diffusion length, were measured for such a structure composed of p-GaP and p-GaAs. The interface recombination velocity was determined from the photoluminescence and the diffusion length of the electrons in the GaAs by a scanned light-spot technique.