Nanostructures with Quantum Dot Clusters: Long Photocarrier Lifetime

Abstract

Major restrictions of semiconductor optoelectronic devices operating at room temperatures are caused by short photoelectron lifetime, which strongly reduces the photoresponse and puts strong limitations on manipulations with photoelectrons. Here we present results of modeling novel optoelectronic materials, based on structures with correlated dot clusters. The main distinctive characteristic of these quantum-dot structures are collective potential barriers around dot clusters. The barriers provide an effective control of photoelectron capture due to separation of highly mobile electron states transferring the photocurrent from the localized electron states in quantum dots. The novel nanostructured materials combine manageable photoelectron lifetime, high mobility, and quantum tuning of localized and conducting states. Thus, these structures have strong potential to overcome the limitations of traditional quantum dot and quantum-well structures. Besides manageable photoelectron kinetics, the advanced quantum-dot structures will also provide high coupling to radiation, low generation-recombination noise, and high scalability.