Photoelectric properties of GaSb Schottky diodes

Abstract

Electrical and photoelectrical properties of GaSb Schottky diodes obtained by evaporating gold metal dots on sulphur treated or chemically etched surfaces of Te-doped n-GaSb crystals (grown from melt by Czochralski method), with Hall carrier density in the range of 1.8–6.5×1017 cm−3, were studied. J/V characteristics with an ideality factor ranging between 1.17 and 1.22 were measured on Schottky diodes prepared on sulphur passivated surfaces. After image force effect correction, photoelectric determination of the barrier height (qΦb=0.598±0.006 eV) has been found to be independent of the surface treatment and, in the case of the sulphur-treated diodes, in good agreement with the value obtained through C−2 vs reverse bias measurements (qΦb=0.6±0.01 eV). Through spectral response analysis of Schottky diodes, an estimation of minority carrier diffusion length value is given. A major role of sulphur passivation on preparation of Schottky barrier with good and well reproducible electrical properties is confirmed.