Control of quantum dot excitons by lateral electric fields

Abstract

The control of exciton wave functions in (In,Ga)As∕GaAs quantum dots through lateral electric fields has been studied by photoluminescence (PL) spectroscopy. p-i-n and n-i-n lateral gate structures were fabricated by ion implantation and subsequent thermal annealing. While single dot spectroscopy shows only small exciton energy shifts when external bias is varied, time-resolved PL reveals strong changes of the exciton lifetime and therefore of the underlying electron-hole overlap, as a consequence of significant lateral carrier displacements within the dots.