Electrochemically growth and characterization of CulnTe_2 chalcopyrite thin films

摘要

Copper indium tellurite (CIT) chalcopyrite compounds were electrochemically grown from an aqueous electrolyte including water-soluble Cu, In, and Te molecular sources onto indium thin oxide-coated glass substrates. CuSO_4·5H_2O, InCl_3, and Na_2TeO_3 were used as copper, indium, and tellurium sources, respectively. Deposition mechanisms of the CIT thin films are explained by cyclic voltammetry (CV) studies. It is also noted that the effect of deposition potential on the electrical, optical, and structural facilities of the electrodeposited CIT thin films. Energy bandgap of the electrodeposited CIT films is in the range of 0.97-1.83 eV. Stoichiometry of the CIT films deposited at - 0.5, - 0.6, - 0.7, and -0.8 V is near to CuInTe_2. We report that the produced CIT films is polycrystalline nature, and CuInTe_2 is a major chalcopyrite phase corresponding to (1 1 2), (2 0 4), and (1 1 6) directions at 2θ～25°, 41°, and 49°, respectively. Hall-effect measurements show that the produced CIT thin films have p-type semiconducting conductivity with the acceptor concentration range of 2.8 × 10~(17) and 2.8 × 10~(18) cm~(-3). The variation of the mobility within 20.4-60.2 cm~2/V s can be explained by the variation of Cu/In ratio within 2.19-0.59. The resistivity of the films is found to vary within 0.011-0.036Ω cm, which is in good agreement with the literature data.