DELAYED LUMINESCENCE INDUCED BY INTERSUBBAND OPTICAL-EXCITATION IN A CHARGE-TRANSFER DOUBLE-QUANTUM-WELL STRUCTURE

Photoluminescence processes in a novel GaAs double quantum well (DQW) structure were studied and found to be controlled by st 10 mu m mid-in frared (MIR) light. In this DQW structure, photogenerated electron-hol e pairs are normally separated into different wells and their radiativ e recombination is inhibited. However, when a MIR light pulse is suppl ied to induce an electron intersubband transition, electrons are effic iently transferred to the hole-rich well, resulting in a significant e nhancement of luminescence. By time shifting the MIR pulse with respec t to he Light pulse for interband excitation, we demonstrated the gene ration of a delayed photoluminescence. Device potentials of dris MIR t o near-infrared conversion are discussed. (C) 1997 American Institute of Physics.