Rapid hot-electron capture in self-assembled quantum dots via phonon processes

Electron capture induced by carrier heating in InAsGaAs quantum dots is studied theoretically. Room temperature capture rates due to single longitudinal-optical (LO) phonons, LO phonons plus acoustic phonons, and two LO phonons are compared. Due to energy broadening from carrier-carrier scattering, single LO-phonon processes are the fastest capture channel. Screening from wetting-layer (WL) carriers is studied comprehensively using a number of screening models. Due to the dispersion of the WL electron-hole plasma and dynamic effects of screening, antiscreening occurs expediting rather than slowing down electron capture, with capture times of several picoseconds when the carrier temperature is 100-200 K above room temperature. © 2006 American Institute of Physics.