Abdulghani Zuhair R, Najm Asmaa Soheil, Holi Araa Mebdir, Al-Zahrani Asla Abdullah, Al-Zahrani Khaled S, Moria Hazim
Department of Mechanical Engineering Technology, Yanbu Industrial College, Yanbu Al-Sinaiyah City, 41912, Kingdom of Saudi Arabia.
Department of Electrical Electronic and Systems Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia (UKM), 43600, Bangi, Selangor, Malaysia.
Sci Rep. 2022 May 16;12(1):8099. doi: 10.1038/s41598-022-12234-0.
Quantum bandgap buffer layers can improve sunlight absorption in the short wavelength region, hence improving the performance of CIGS solar cells. In this study, we use numerical modelling to determine the impact of various buffer layers' electrical characteristics on the performance of CIGS thin film photovoltaic devices, particularly, carrier concentration and the quantum effect. As well AgS buffer layer has been experimentally examined to fulfilment its effect in term of bulk and quantum bandgap. Experimental results depicted that, AgS QDs has polycrystalline nature of films, with smooth surface roughness, and average diameter 4 nm. Meanwhile, a simulation revealed that the Fermi level of the (n-buffer layer) material shifts closer to the conduction band with an increase in carrier concentration. The findings indicate that, a buffer layer with a wider bandgap and carrier concentration is an essential demand for achieving a device with a higher conversion efficiency and a broader bandgap-CBO window. It was attributed to beneficial synergistic effects of high carrier concentration and narrower depletion region, which enable carriers to overcome high CBO barrier. Most importantly, modelling results indicate that the optic-electrical characteristics of the buffer layer are critical in determining the progress of a CIGS solar cell.
量子带隙缓冲层可以改善短波长区域的太阳光吸收，从而提高铜铟镓硒（CIGS）太阳能电池的性能。在本研究中，我们使用数值模拟来确定各种缓冲层的电学特性对CIGS薄膜光伏器件性能的影响，特别是载流子浓度和量子效应。此外，还对硫化银（AgS）缓冲层进行了实验研究，以验证其在体相和量子带隙方面的效果。实验结果表明，AgS量子点具有多晶薄膜性质，表面粗糙度平滑，平均直径为4纳米。同时，模拟结果显示，随着载流子浓度的增加，（n型缓冲层）材料的费米能级向导带移动。研究结果表明，具有更宽带隙和载流子浓度的缓冲层是实现具有更高转换效率和更宽带隙-导带偏移（CBO）窗口器件的基本要求。这归因于高载流子浓度和较窄耗尽区的有益协同效应，使载流子能够克服高CBO势垒。最重要的是，模拟结果表明缓冲层的光电特性对于确定CIGS太阳能电池的进展至关重要。
