MONTE-CARLO SIMULATION OF IMPACT IONIZATION IN PHOTODETECTORS

The authors have studied impact ionisation in optical detectors using a self-consistent Monte Carlo method. Current multiplication was found to be sensitive to both the applied potential and the incident light intensity. The amount of current multiplication was significantly high er than might be expected From a naive interpretation of the nominally applied field and this was attributed to screening effects within the device. The potential within the device was also significantly affect ed by the impact ionisation process and this in turn gave rise to an i nteresting structure (oscillations) in the current at higher incident light intensities and potentials.