INFLUENCE OF SULFIDATION TREATMENT ON THE PERFORMANCE OF MIDINFRARED INASPSB INAS DETECTORS/

The influence of sulphidation treatment on the performance of room tem perature InAsPSb/InAs photodetectors was investigated. Measurements of photoresponsivity, external quantum efficiency and detectivity of the detectors with and without the sulphidation treatment showed that aft er the sulphidation treatment the sensitivity of the detectors improve d 1.5 times. A study of the chemical state of sulphur on an (NH4)(2)S- x-treated InAs(001) surface was performed by high-resolution X-ray pho toelectron spectroscopy (XPS). The chemical state of sulphur bonded to indium (In) and arsenic (As) atoms for the as-treated surface was obs erved showing the termination of the dangling bonds at the surface by the sulphidation treatment. This gives rise to a remarkable decrease o f surface recombination center density and results in the increase of photodetector sensitivity.