MONTE-CARLO STUDIES OF INTERSUBBAND RELAXATION IN SEMICONDUCTOR MICROSTRUCTURES

In recent years, a number of time-resolved photoexcitation experiments have been reported which directly measure the decay of photoexcited carriers due to inter-subband scattering in semiconductor quantum wells and superlattices. Various techniques such as differential transmission, photoluminescence spectroscopy and Raman spectroscopy have probed different regimes of this non-equilibrium carrier relaxation. Particle simulation using Monte Carlo techniques has proved particularly useful for modelling the non-stationary behaviour of carriers during and after ultrafast laser excitation in such experiments. Here a discussion is given of hot carrier dynamics in heterojunction systems during photoexcitation, and the modelling of the dynamics using ensemble particle simulation. Comparison is made with different experiments which measure the effects of intersubband relaxation in single and multiple quantum wells.