Characterisation of MBE Grown HgCdTe Using Scanning Laser Microscopy

The performance of infrared detectors fabricated from semiconducting HgCdTe is highly dependent on the minority carrier lifetime of the material. A high minority carrier lifetime is required to achieve good signal to noise ratio in both photoconductive and photovoltaic infrared detectors. In this work a scanning laser microscope has been used to investigate the minority carrier lifetime in n-type epitaxial HgCdTe using the photoconductive decay technique and spatial photoresponse. The results indicate that the MBE grown HgCdTe is of high quality and the lifetime is limited by the device surface passivation.