12-16 September 2005
University of Liverpool
Europe/Zurich timezone

Mobility-lifetime products of epitaxial GaAs materials

Sep 15, 2005, 10:30 AM
University of Liverpool

University of Liverpool

Greenbank Conference Park
Board: P40/2
Contributed Poster New Solid-State Detector Technology P : Coffee and Poster Session


Dr J.C. Bourgoin (Université Pierre et Marie Curie)


Self-supported thick (larger than 200 microns), non intentionally doped, epitaxial GaAs layers are good candidates for X-ray imaging for the following reasons. Their electronic properties are homogeneous over large areas (4 inches diameter), they can be grown at low cost, the technology to realize pixel detectors of any size is standard, the defect concentration is very low and the fluorescence yield is low. The low defect concentration permits a large minority carrier lifetime, which is at least 100 times larger than in bulk grown materials. Here we demonstrate that the mobility-lifetime product is high. Using Deep Level Transient Spectroscopy combined with photon counting, we evaluate the electron and hole lifetimes to be at least 10- 6 s, leading to electrons and holes mobility-lifetime products of 8×10-3 cm2V-1 and 4×10-4 cm2V-1, which are 100 times higher than the standard values (taken from bulk materials) attributed to GaAs, i.e. 8×10-5 cm2V-1 for electrons and 4×10-6 cm2V-1 for holes; about 2 times larger than for the best CdTe materials, i.e. 3×10- 3 cm2V-1 for electrons and 2×10-4 cm2V-1 for holes.

Primary author

Guoaci Sun (Université Pierre et Marie Curie)


Dr J.C. Bourgoin (Université Pierre et Marie Curie)

Presentation materials