Optical measurement system for characterizing compound semiconductor interface and surface states

An optical measurement system that is useful for the characterization of interface and surface states on a wide variety of compound semiconductor material systems has been developed. The PC-based measurement system, using argon ion laser excitation from 10/sup -1/ to 10/sup 4/ W/cm/sup 2/ power density and a light spot focused to a FWHM of 35 /spl mu/m, acquires photoluminescence (PL) spectra from a semiconductor material system over a dynamic intensity range of more than eight orders of magnitude. The measured PL intensities that are evaluated using an extended, numerical self-consistent drift-diffusion model provide properties of interface and surface states such as density and capture cross section as well as derived quantities including nonradiative interface and surface recombination velocity.