Reduction of Grain Boundary Effects in Indium Phosphide Films by Nitridation

Abstract

Indium phosphide, a direct gap semiconductor with a room temperature energy gap of 1.35 eV, is a promising photovoltaic material for thin film devices. Thin films of indium phosphide have been deposited on tungsten‐coated graphite substrates by the reaction of indium, hydrogen chloride, and phosphine in a gas flow system. Without intentional doping, the deposited films are n‐type with a carrier concentration of about 1017 cm−3. Schottky barriers prepared from these films have been found to exhibit low rectification ratios, high dark currents, and poor photovoltaic response due to the shunting effects of grain boundaries. The grain boundary effects can be partially reduced by heat‐treatment in an ammonia atmosphere, converting the surface of grains into indium nitride. The formation of indium nitride has been verified by Auger electron spectroscopy and x‐ray photoelectron spectroscopy.

A One‐Volt p ‐ InP / n ‐ CdSe Regenerative Photoelectrochemical Cell

“…Less work has been performed on the preparation of polycrystalline p-lnP; however, encouraging progress is being made for solid state cells using chemical vapor deposition techniques (22)(23)(24).…”