Effect of Copper-vacancy on the Electrical,Optical and Thermoelectric Properties of CuInTe2 by the First-principles Study

摘要：The effects of copper-vacancy on the electrical, optical and thermoelectric properties of CuInTe2 have been investigated by the first-principles calculations and semi-classical Boltzmann theory. The estimated results of copper vacancy formation energies for Cu1-xn Te2(x = 0,1/16, 1/8 and 1/4) showed it is more difficult to prepare the sample with higher copper vacancy concentration. From the calculated energy band structures with MBJ-GGA, it can be seen that they are p-type semiconductors and the energy gap values increase with the vacancy concentration increasing. The wavelength is smaller than 460 nm, and the high copper vacancy concentration(x =1/4) is helpful to the values of absorption coefficient, while above 460 nm, the lower copper vacancy concentration(x = 1/16) is able to enhance the absorption coefficient. The lower copper vacancy concentration(x = 1/16) is more favorable to improve the power factor in low or middle temperature. However, the high copper vacancy concentration(x = 1/4) is better in high temperature. These results give hints for the design of CuInTe2 as the good photovoltaic and thermoelectric materials.