en عمومى General پژوهشي Research In this paper, a thin film silicon solar cell with anti-reflection coatings on front surface and the combination of periodic grating and photonic crystal on its back surface has been considered. The thickness and number of anti-reflection coatings, as well as the geometric and physical parameters of photonic crystal and grating are optimized to increase the optical absorption of solar cell. The simulations have been performed using the finite difference time domain method with Lumercial software. The results show that the optical absorption of solar cell has been increased significantly by utilizing the anti-reflection coatings, photonic crystal and grating. <div></div> Photonic crystal, antireflection coating, silicon solar cell. 129 134 http://ijop.ir/browse.php?a_code=A-10-697-1&slc_lang=en&sid=1 Sepideh Esmaeili Germezgholi sepidehesmaili72@gmail.com 10031947532846003463 10031947532846003463 No Department of Physics, University of Tabriz, Tabriz, Iran Behrooz Rezaei rezaeibhr@yahoo.com 10031947532846003464 10031947532846003464 Yes Department of Physics, University of Tabriz, Tabriz, Iran Sohrab Ahmadi-Kandjani s_ahmadi@tabrizu.ac.ir 10031947532846003465 10031947532846003465 No Department of Physics, University of Tabriz, Tabriz, Iran, Research Institute for Applied Physics and Astronomy, University of Tabriz, Tabriz, Iran