Optical and recombination parameters of GaSe obtained from interference spectroscopy of transmittance, reflectance, photoconductivity and photomagnetoelectric responses

Cleaved films of crystalline GaSe of thickness from 1500 nm to 5000 nm were investigated using optical transmittance, reflectance, photoconductivity (PC) and photoelectromagnetic effect. The investigations were performed at room temperature for different illumination intensities and wavelengths (from 400 nm to 1500 nm). The oscillatory behaviour of the measured spectral dependencies due to interference of radiation internally reflected in the samples were registered. The least square fitting of the experimental results with theoretical formulae allowed to determine the spectral dependencies of real part of refractive index and absorption coefficient of radiation as well as the power coefficient in the power law dependence of PC on illumination intensity. The necessity of new theoretical description of the investigated effects is proposed.