Zaka Awais, Alhassan Saeed, Nayfeh Ammar
Department of Chemical and Petroleum Engineering, Khalifa University of Science and Technology, Abu Dhabi, 127788, United Arab Emirates.
Department of Electrical Engineering, Khalifa University of Science and Technology, Abu Dhabi, 127788, United Arab Emirates.
Sci Rep. 2025 May 28;15(1):18763. doi: 10.1038/s41598-025-03692-3.
Iron pyrite (FeS) has emerged as a promising photovoltaic material due to its high absorption coefficient, earth abundance, and non-toxicity. However, its low power conversion efficiency, largely attributed to structural defects and phase impurities, has limited its application in solar cells. This study explores the solvothermal synthesis of iron pyrite under varying reaction conditions to optimize its phase purity and optical properties. X-ray diffraction and scanning electron microscopy confirm that phase-pure pyrite is obtained at 180 °C with a stoichiometric sulfur ratio, while higher temperatures and non-stoichiometric sulfur concentrations lead to the formation of secondary phases such as pyrrhotite and marcasite. Spectroscopic ellipsometry is used to determine the optical properties, revealing a direct band gap of 2.8 eV and an indirect band gap of 0.95 eV for phase-pure pyrite. The presence of secondary phases significantly alters the band structure and optical properties, leading to defect-related recombination highlighting the importance of precise synthesis control to achieve phase-pure pyrite with desirable optical characteristics, providing valuable insights into its potential for photovoltaic applications.
黄铁矿（FeS）因其高吸收系数、在地壳中储量丰富且无毒，已成为一种很有前景的光伏材料。然而，其低功率转换效率在很大程度上归因于结构缺陷和相杂质，这限制了它在太阳能电池中的应用。本研究探索了在不同反应条件下溶剂热合成黄铁矿，以优化其相纯度和光学性质。X射线衍射和扫描电子显微镜证实，在180°C且硫比例为化学计量比的条件下可获得纯相黄铁矿，而较高温度和非化学计量比的硫浓度会导致形成诸如磁黄铁矿和白铁矿等次生相。使用光谱椭偏仪测定光学性质，结果表明纯相黄铁矿的直接带隙为2.8 eV，间接带隙为0.95 eV。次生相的存在显著改变了能带结构和光学性质，导致与缺陷相关的复合现象，突出了精确合成控制以获得具有理想光学特性的纯相黄铁矿的重要性，为其在光伏应用中的潜力提供了有价值的见解。
