Temperature Dependence of Photoluminescence Decay Time in Tunneling Bi-Quantum-Well Structures

Abstract
We studied the nonresonant electron tunneling time in tunneling bi-quantum-well structures with a pump-probe photoluminescence (PL) system using optical mixing. The PL decay time of narrow wells for an Al x Ga1-x As (x=0.51) barrier of 4.0 nm, determined by tunneling, decreases from 40 ps to 24 ps as the temperature increases from 6 K to 132 K. We attribute this to electrons in an exciton state thermalizing into free electrons having a faster tunneling rate.