Radiative Properties Of Variable Cross Section Grating Structure Of CZTS Thin Film Solar Cell

With the rapid growth of energy demand and global warming, we are confronted with more and more challenges every rising day related to energy generation. The traditional ways of energy generation by fossil fuels are drawn back by the concept of harvesting energy through Renewable Energy Sources during this century. There are different types of renewable energy sources but the one resource which has attracted wide attention is the Solar Energy. Solar energy source is known as reliable and clean renewable energy. The main key factor for harvesting the solar energy is solar cell. To extract the maximum energy from sun, compatible, reliable and efficient solar cell designs are needed. To obtain this goal we studied the thermal Radiative properties of CZTS thin film solar cell and we included tapered grating structure of Aluminum Zinc Oxide (AZO) on the surface, in order to enhance the light absorption efficiency of thin film solar cell.In order to understand the phenomenon of grating structures, Anti Reflective Silicon on Insulator Triangular and Square grating Structures were simulated on the facets of the planar waveguides. Results obtained from simulations explain that triangular grating structures provided reduction in reflectance when the length of gradient index was increasing, and the power transmittance was higher at shorter wavelengths. In case of the square grating structures the power transmittance of the device was higher at higher wavelengths.Simulations were performed on CZTS thin film solar cell using FDTD method; the Continuous Gaussian Wave of1.55wavelength light incident input applied. Simulations were performed in by three different methods. Results indicated that the heat absorption efficiency of the solar cell is increased when grating structures are designed on the surface of the solar cells. The efficiency was increased by4%. It was also observed that when the grating period “k” is varied the absorption efficiency is also varied. Higher the grating period lower the absorption efficiency and vice versa. The weighted reflectance of the CZTS TFSCs having grating structure is reduced to1%value. It was also observed that maximum absorptance efficiency occurs at lower wavelengths of480nm to800nm. When the wavelength is increased then there is no noticeable change in efficiency.