| Work Detail |
Chinese researchers have attempted to increase the efficiency of a heterojunction solar cell by using an indium tin oxide buffer layer. This innovation reportedly resulted in a 0.1% efficiency increase due to the optimization of the short-circuit current density and fill factor. A group of Chinese researchers has fabricated a heterojunction (HJT) solar cell based on an indium tin oxide (ITO) buffer layer with the aim of improving the devices optical and electrical properties. “Indium tin oxide (ITO) layers prepared at high power have significantly contributed to improving the crystalline quality of the films and the capacity of silicon heterojunction solar cells,” corresponding author Daxue Du told pv magazine . “However, it often causes sputtering damage, resulting in degraded photovoltaic performance. In this work, we designed an ITO buffer layer on industrial SHJ solar cells and analyzed the optical and electrical performance in detail using the monolayer ITO film as a reference.” The scientists built the cell using a 120 µm, 182 mm × 105 mm n-type monocrystalline silicon wafer; the hydrogenated amorphous and microcrystalline silicon passivation films were passivated using plasma-enhanced chemical vapor deposition (PECVD), and the ITO layer was deposited using physical vapor deposition (PVD). The silver grids were fabricated by screen printing and annealed at 200 °C. The ITO bilayer was specifically designed to achieve improved electrical performance in the thin middle layer prepared at low power and O2 concentration, while improving optical performance in the thicker outer layer prepared at higher power and O2 concentration, the group explained. It was designed to achieve smaller refractive indices and lower extinction coefficients, resulting in higher short-circuit current generation. Tested under standard lighting conditions, the cell achieved a power conversion efficiency of 25.36%, which the scientists say is 0.1% higher than that of devices without the ITO buffer layer. Both carrier concentration and mobility improved due to the decrease in chemisorbed oxygen and the increase in oxygen vacancies, respectively, resulting in lower resistivity and a higher fill factor. We believe this work demonstrates a potentially viable approach to achieving high-performance and high-efficiency industrial silicon heterojunction solar cells, Du concluded. The new solar cell concept is described in the study “ Optimized optical and electrical properties for silicon heterojunction solar cells with an indium tin oxide buffer layer,” recently published in Solar Energy Materials and Solar Cells . The research team included academics from China’s Shanghai Hency Solar Technology Co., Ltd. and Shanghai Jiao Tong University. Other researchers at Shanghai Jiao Tong University recently evaluated the impact of harvesting on the fabrication of heterojunction (HJT) solar cell technologies. |
