Electronic Structure Engineering of Antimony-based Optoelectronic Devices

University Of Iowa, Iowa City IA

Investigators

Abstract

Flatte' 0000556 The PI presents here a coherent theoretical program investigating the optoelectronic properties of antimony-based heterostructures. Great flexibility has already been demonstrated in the design of optoelectronic devices which use materials based on the (roughly) lattice matched AlGaSb/InAs material system. Such materials have been used in mid-wave infrared (MWIR) lasers, long-wave infrared (LWIR) detectors, and resonant interband tunneling diodes (RITD's). These MWIR and LWIR lasers and detectors have broad spectroscopic applications to environmental monitoring and non-invasive medical sensing. RITD's, which have the largest peak to valley current ratios of any RTD devices, are intended for use in a variety of microwave and fast digital device applications. For each type of device the expected properties of antimony-based heterostructures are superior to those of competing systems. Current barriers to the realization of these superior properties are: (1) maturation of growth and processing technology, (2) detailed experimental probes of the material properties of device elements, and (3) theoretical understanding and modeling of materials and devices. The wide range of choices and applications of antimony-based heterostructures has made efforts in this last category vital to further progress in the field. In the proposed effort progress in understanding the properties of materials and devices, and in designing better devices, will be accomplished principally through efforts to (1) develop appropriate and accurate transport models, (2) improve the accuracy of the electronic structure models currently used, and (3) account for interface chemistry and structure in this mixed-anion system. The P.I.'s have been engaged in the past in several collaborative efforts with non-academic institutions, including industrial and government laboratories, and they are committed to continuing these efforts in the future. Specifically, the RITD effort will be coordinated with efforts at HRL and JPL, and the interface modeling effort at HRL.