Optical and electronic analysis of Al doped CuInSe2thin film based flexible solar cells

Abstract

A solution to low cost electricity has been provided by the innovation of Thin-film flexible photovoltaics or solar cells which include a wide variety of organic, inorganic and organic-inorganic solar cells laid over substrates that are flexible and offer high-Throughput technologies. The highest efficiencies are exhibited by CIGS among all thin-film PV devices. Thus justifying it to be present as the most appropriate and optimal thin film PV material with an efficiency of 18.8 %. Ternary chalcopyrite compounds (CuGaSe2, CuInS2, CuInSe2, CuAlSe2) offer large optical absorption coefficient and act as an absorber in thin films solar cells. In this paper we have presented a Density Functional Theory calculation of Al-doped CuInSe2 thin film of vacuum size 10 Å offering a bandgap nearby to the bulk CuInSe2 thus stating its apt configuration. The analysis of electronic and optical properties of this system is deduced by Trans-Blaha Modified Becke Johnson (TB-mBJ) functional and the bandgap is observed to be 1.02 eV. By increasing the amount of Al in the system we can increase the bandgap to its suitable range of solar spectrum thus define the usage of this thin film in optoelectronic applications.