COPPER INDIUM DISELENIDE SINGLE-CRYSTAL AND THIN-FILM INFRARED-SENSORS

Copper indium diselenide (CIS) and copper indium gallium diselenide (C IGS) are now well established as exceptionally efficient semiconductor s with potential applications in the fields of solar cells, infrared r adiation monitors and fibre optic infrared detectors. CIGS can be dope d both p- and n-type and has a direct band gap which can be varied bet ween 1.02 eV and 1.68 eV. Single-crystal CIS infrared detectors were p roduced on p-type substrates. The devices displayed photosensitivity s ignificantly superior to that of silicon in the infrared at wavelength s up to 1.3 mu m. Thin films were deposited by pulsed laser ablation o f polycrystalline CIS targets using a XeCl excimer laser. The electric al and photo response of the thin film devices, while inferior to that from single crystals, indicated that laser ablated thin-film CIS sens ors have potential for use as infrared detectors.