en عمومى General پژوهشي Research <p class="Abstract" style="text-align: justify;">In this paper, tetragonal chalcopyrite (CIGS) Cu(In_xGa_1-x)Se₂ with x=0, 0.5, 0.8, 1 are synthesized by heating-up method. These nanoparticle structures differ in morphology and absorption properties due to the synthesis temperatures of 250, 255, 260, 265, 270 and 280 &ordm;C, and gallium molar ratio over the total gallium and indium contents. These features are studied using scanning electron microscope, X-ray diffraction and absorption spectroscopy in visible, ultra-violet and near-infrared wavelengths. Results indicate that by increasing gallium content, absorption edge rises toward the visible light. Any modification in the absorption edge changes the band gap and as a result the energy gap and the absorption of cell increases considerably. Also in the heating-up method, increasing the reaction temperature improves nanoparticles crystallites. This leads the absorption improvement and higher cells efficiency. Produced nanoparticles are spherical shape with are varying the diameter around 30-80 nm.</p> CIGS nanoparticles, solar cells, non-vacuum method, heating-up method, characterization of CIGS 13 20 http://ijop.ir/browse.php?a_code=A-10-86-7&slc_lang=en&sid=1 Hadi Zarei zarei.physics@gmail.com 10031947532846002124 10031947532846002124 No Department of Physics, Faculty of Basic Sciences, Tarbiat Modares University, Rasoul Malekfar Malekfar@Modares.ac.ir 10031947532846002125 10031947532846002125 Yes Department of Physics, Faculty of Basic Sciences, Tarbiat Modares University,