Temperature dependence of the avalanche multiplication process and the impact ionization coefficients in Al0.8Ga0.2As

The temperature dependence of the avalanche multiplication process at soft X-ray energies in Al0.8Ga0.2As avalanche photodiodes (APDs) is investigated at temperatures from +80 to −20 °C. The temperature dependence of the pure electron initiated multiplication factor (Me) and the mixed carrier initiated avalanche multiplication factor (Mmix) is experimentally measured. The experimental results are compared with a spectroscopic Monte Carlo model for Al0.8Ga0.2As diodes from which the temperature dependence of the pure hole initiated multiplication factor (Mh) is determined. The temperature dependences of the electron and hole ionization coefficients in Al0.8Ga0.2As are reported for the first time.