Surface photovoltage spectroscopy of semi-insulating GaAs in the 800–1100 nm range

Surface photovoltage spectroscopy (SPS) studies on thick semi-insulating (SI) GaAs wafers have been done in the range 800–1100 nm using chopped light geometry. SPS peaks at 880 nm, 900 nm, and a broadband in the range 930–1080 nm have been observed. These observations are important as SPS is routinely used to study absorption-related features in InAs self-organized quantum dots grown on SI GaAs. The effect of the ambient and chopping frequencies on SPS spectra is also presented.