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 intersubband scattering in a wide quantum well are investigated. The scattering rate is significantly reduced by the screening effects around the well width with Δ E 21 = E LO . From a comparison with experimental results, it is found that the electron temperature estimated with screening effects is higher than that estimated without screening effects. This is due to the fact that the intrasubband relaxation time with screening effects is longer than that without screening effects. With screening effects, the lifetime significantly decreases with increasing applied electric field. On the other hand, the lifetime calculated without screening effects is nearly independent of any applied electric field. The results calculated with screening effects agree well with the experimental results.