Germanium photodetectors with induced p-n junctions

An experimental investigation has been made of optoelectronic carrier transport processes in Au-Ge contacts and their dependence on temperature, which shows that these devices behave as "induced" p⁺-n junctions rather than as Schottky barriers. The dark currents are due predominantly to minority-carrier injection in forward bias, and to generation in the quasi-neutral region in reverse bias. The devices are formally equivalent to germanium p⁺-n junction photodetectors with diffused or ion-implanted junctions, but require neither high-temperature fabrication processes nor high dopant concentrations in the surface region.