Electrical and luminescent properties of CuGaSe2 crystals and thin films

CuGaSe2 thin films with thicknesses of about 2 mum were prepared by flash a nd single source evaporation onto mica and (I I 0)-oriented ZnSe substrates in the substrate temperature range 150-450 degreesC. The obtained polycrys talline CuGaSe2 films had the chalcopyrite structure with the predominant g rowth direction [221]. Hall effect, conductivity and luminescence measureme nts have been carried out on CuGaSe2 thin films and source materials: CuGaS e2 single crystals grown by Bridgman technique and by chemical vapour trans port using I-2 as transport agent. All films and crystals are p-type. Two a cceptor levels with ionization energies E(A1)similar to 50-56meV and E(A2)s imilar to 130-150meV have been identified as due to Ga vacancy and presence of Se atoms on interstitial sites respectively. (C) 2001 Elsevier Science B.V. All rights reserved.