Abstract

GaSb has a number of known applications, primarily in optoelectronics, such as infrared detectors, thermophotovoltaic converters and LED ’s. However, the transport properties of this material (both the standard p-type and more uncommon n-type) have generally been restricted to bulk GaSb. GaSb also has a lower electron effective mass than it’s better-studied counterpart, GaAs, however it has a large number of defects regardless of growth method, producing a high acceptor background.

Theoretical transport results were produced using Nextnano software [1], with the aim of measuring confined two-dimensional electron gas devices (a system not previously reported in GaSb). GaSb/Al0.2Ga0.8Sb heterostructures were grown at Lancaster University by molecular beam epitaxy, with Hall bars of varying sizes subsequently fabricated. Measurements of these devices yielded a higher accepting background than intended and ultimately resulted in p-type devices.

I will discuss the theoretical and experimental results of these devices, as well as subsequent growth trials of this material, the problems we faced and how we are combating them.

[1] S. Birner et al., Acta. Phys. Polonica. A 110 , 111, (2006).