N-type GaSb single crystals with high below-band gap transmission

Te-doped GaSb single crystals are studied by measuring Hall effect, infrared (IR) transmission and photoluminescence (PL) spectra. It is found that the n-type GaSb with IR transmittance can be obtained as high as 60% by the critical control of the Te-doping concentration and electrical compensation. The concentration of the native acceptor-associated defects is apparently low in the Te-doped GaSb compared with those in undoped and heavily Te-doped GaSb. The mechanism for the high IR transmittance is analyzed by considering the defect-involved optical absorption process.