Electron Capture into Quantum Wells via Scattering by Electrons, Holes, and Optical Phonons

TL;DR

This paper calculates electron capture times in GaAs quantum wells due to various interactions, revealing oscillatory behavior with well width and analyzing the effects of exchange and degeneracy on capture dynamics.

Contribution

It provides detailed calculations of electron capture times considering multiple interactions and explores the physical origins of oscillations and the influence of exchange and degeneracy effects.

Findings

Capture times oscillate with quantum well width.

Electron-hole capture is significantly slower than electron-polar optical phonon capture.

Exchange effects roughly double the electron-electron capture time.

Abstract

Electron capture times due to the electron-electron (e-e), electron-hole (e-h) and electron-polar optical phonon (e-pop) interactions are calculated in the GaAs quantum well (QW) with electron and hole densities 10^11 cm^-2. The calculated capture times oscillate as a function of the QW width with the same period but with different amplitudes. The e-h capture time is two to four orders larger and the e-e capture time one to three orders larger than the e-pop capture time. The exceptions are the QW widths near resonance minima, where the e-e capture time is only 2-3 times larger and the e-h capture time 10-100 times larger. Different physical origin of the oscillatory behavior is demonstrated for the e-e and e-pop capture times. Effects of exchange and degeneracy on the e-e capture are analysed. The exchange effect increases the e-e capture time approximately two times while the degeneracy does not change the capture time except for the QW depths and widths near the resonance.