Microscopic analysis of generation-recombination noise in semiconductors under dc and time-varying electric fields

We present a microscopic analysis of current fluctuations in a semiconducto r sample in the presence of trapping-detrapping processes and conventional scattering mechanisms. An ensemble Monte Carlo simulation is used for calcu lations. To ensure the linearity of the system, we use a model where the ch aracteristic times of the different microscopic mechanisms are considered a s energy independent. We analyze the behavior of thermal and generation-rec ombination noise spectra under static (dc field) and time-varying (ac field ) conditions. Under dc bias we confirm the validity of the microscopic mode l by comparing the results of the simulation with analytical predictions. W hen an ac field is applied, amplitude modulation of the semiconductor respo nse takes place due to generation-recombination processes. This modulation leads to the upconversion of the low-frequency generation-recombination spe ctrum, which is evidenced (even in the absence of dc current) and analyzed under different physical conditions. (C) 2000 American Institute of Physics . [S0021-8979(00)09114-3].