Preparation and characterization of Cu(In1-xGax) 3Se5 thin films

Abstract

Polycrystalline Cu(In1-xGax)3Se 5 thin films were prepared by four source evaporation with controlling and shielding of the molecular beams from elemental sources. Ga content x, can be controlled by deposition times of CuIn3Se 5 and CuGa3Se5 layers, which form Cu(In 1-xGax)3Se5 films through the interdiffusion. X-ray diffraction analyses showed that the films with x≲0.5 have an ordered vacancy chalcopyrite and the films with x≳0.5 have a zinc blende structure. The optical band gap of the films linearly increased from 1.23 eV (x=0) to 1.85 eV (x=1) with increasing Ga content. The conductivity of the films was about 10-6/Ω cm and about 10-7/Ω cm under and above x=0.3, respectively.© 1995 American Institute of Physics.