STRUCTURAL AND ELECTRICAL CHARACTERISTICS OF CUINSE2 THIN-FILMS GROWN BY 3-SOURCE COEVAPORATION

CuInSe2 thin films were deposited on glass or glass/Mo substrates ah 350 degrees C by the three-source coevaporation method. It was found from composition analysis that the Cu/In mole ratio of the p-type thin films fall in the 0.5-3.1 range. The X-ray diffraction intensity of the strong chalcopyrite (112) peak showed a remarkable increase with increasing Cu/In ratio: and a relatively weak diffraction peak corresponding to Cu2-xSe appeared when Cu/In > 0.9. It was found that with increasing Cu/In ratio the resistivity showed a dramatic decrease from similar to 10(2) Ohm . cm to similar to 10(-3) Ohm . cm while the hole concentration changed abruptly from similar to 10(17) cm(-3) to similar to 10(21) cm(-3). It is concluded that low-resistivity p(+)-CuInSe2 and high-resistivity p-CuInSe2 layers can be successfully synthesized under the conditions of Cu/In > 2 and Cu/In similar to 0.5, respectively,