Photoresponse in nonuniform semiconductor junctions under infrared laser excitation

Abstract

The peculiarities of a photovoltaic effect in Ti/n-Si Schottky contact and GaAs n-n+ junction at excitation wavelengths 10.6 micrometers , 2.8 micrometers and 2 micrometers has been investigated experimentally. When the incident photon hv energy is lower than Schottky barrier height the photoresponse nonlinearly depends on laser intensity. The results are interpreted by electron emission over the barrier due to multiphoton and multistep excitation. When hv is greater than the diffusion potential of GaAs n-n+ junction a linear relation between the photovoltage and the laser intensity is observed.