Photothermal Investigation of Te-Doped Bulk Gasb: Correlation between Non-Radiative Lifetime and Thermal Diffusivity

Photothermal deflection PTD is used in order to reveal the influence of Te doping on non radiative carrier lifetime for GaSb bulk sample when illuminated by a modulated and monochromatic light beam. Theoretical simulations are obtained from an adapted theoretical model, based on the resolution of both heat and carrier diffusion equations. Auger recombination coefficient obtained from the linear relation between lifetime and the inverse of squared concentration is in agreement with literature. Moreover, it is found that low n-doping reduces the surface recombination velocity S because of dangling bonds neutralisation at the surface. However for higher doping concentration, S is enhanced by Te doping.