Abstract
Ag/p-InP/p-InGaAs Schottky photodiodes were fabricated with the aim of expanding the spectral response of Ag/p-InP Schottky diodes in the violet and visible region to the infrared region, by adding a p-InGaAs layer to form a heterostructure. The p-InP/p-InGaAs heterostructure was formed by LPE growth and selective etching from a p-InGaAs/p-InP/InGaAsP/InP multiple-layer heterostrucure. A high barrier-height(∼0.8 eV) Schottky contact on the Ag/p-InP gave the heterostructure diodes a low reverse leakage current at room temperature. The diodes are shown to have a very wide spectral response, from 0.4 µm to 1.65 µm, with a fairly flat responsivity and a response-time of 0.5 µs when their diameter is 0.4 mm.