Screening effects on electron-longitudinal optical-phonon intersubband scattering in wide quantum well and comparison with experiment

Screening effects on the electron-longitudinal optical (LO)-phonon intersub band scattering in a wide quantum well are investigated. The scattering rat e is significantly reduced by the screening effects around the well width w ith DeltaE(21) = E-LO. From a comparison with experimental results, it is f ound that the electron temperature estimated with screening effects is high er than that estimated without screening effects. This is due to the fact t hat the intrasubband relaxation time with screening effects is longer than that without screening effects. With screening effects, the lifetime signif icantly decreases with increasing applied electric field. On the other hand , the lifetime calculated without screening effects is nearly independent o f any applied electric field. The results calculated with screening effects agree well with the experimental results.