4×4 ZnSSeTe/ZnSe/GaAs PIN Photodiode Array

N-ZnSSeTe/i-ZnSe II-VI epitaxial layers were grown on p-type GaAs substrate by molecular beam epitaxy (NBE). The II-VI layers play both as a window layer and as a short wavelength absorption layer. The GaAs depletion layer was the main absorption layer. For the device fabrication, the 4×4 device isolation pattern was defined by the conventional photolithography, and etched by a chemical solution of K2Cr2O7 : H2SO4: H2O = 1 g : 10 mL : 20 mL. After finished the device, the current-voltage characteristics of the ZnSSeTe/ZnSe/GaAs PIN photodiode array were measured by an HP-4155B semiconductor analyzer. The corresponding responsivities were also measured by using a xenon lamp through a monochromator from 200 nm to 970 nm. At a reverse bias of 5V, the photo-to-dark current ratio has a magnitude over four orders, and the dominated spectral response has a wide-flat spectral range of 460 nm - 880 nm.