Illumination dependence of I–V and C–V characterization of Au/InSb/ InP(1 0 0) Schottky structure

The effects of surface preparation and illumination on electric parameters of Au/InSb/InP(100) Schottky diode were investigated, in the later diode InSb forms a fine restructuration layer allowing to block In atoms migration to surface. In order to study the electric characteristics under illumination, we make use of an He–Ne laser of 1 mWpower and 632.8 nm wavelength. The current–voltage I(VG), the capacitance–voltage C(VG) measurements were plotted and analysed. The saturation current Is, the serial resistance Rs and the mean ideality factor n are, respectively, equal to 2.03 10 5 A, 85 V, 1.7 under dark and to 3.97 10 5 A, 67 V, 1.59 under illumination. The analysis of I(VG) and C(VG) characteristics allows us to determine the mean interfacial state density Nss and the transmission coefficient un equal, respectively, to 4.33 1012 eV 1 cm 2, 4.08 10 3 under dark and 3.79 1012 eV 1 cm 2 and 5.65 10 3 under illumination. The deep discrete donor levels presence in the semiconductor bulk under dark and under illumination are responsible for the non-linearity of the C 2(VG) characteristic.