Laser beam induced current for qualitative evaluation of HgCdTe van der Pauw sample uniformity

HgCdTe is the preferred semiconductor for fabrication of high-performance infrared (IR) detectors. This material also typically contains multiple carrier species for charge transport, which makes characterisation of the mobility and concentration of each species particularly difficult. Accurate carrier transport characterisation can be achieved by quantitative mobility spectrum analysis of variable-magnetic-field Hall and resistivity data, but this imposes certain conditions concerning sample uniformity and homogeneity. Laser beam induced current (LBIC) is a non-destructive characterisation technique that can be used to qualitatively investigate the electronic properties of HgCdTe samples, specifically including electrically-active defects and p-n junctions. Non-uniformity in the LBIC profiles can also be related to ill-conditioned Hall and resistivity data.