Photoresist Microlens Arrays Fabricated by Nanoimprint Technique to Improve the Photoelectric Conversion Efficiency of Solar Cells

Silicon solar cells have the advantages of non-toxicity, reliability, low price, and stability. Microlens arrays (MLAs) are widely used in solar cells to improve photoelectrical conversion efficiency (PCE). In this research, different MLAs mold was designed by a method of thermal reflow. Then the photoresist film MLAs structure was replicated on the surface of silicon solar cells through UV nanoimprint technology. The optical transmission and surface morphology of these photoresist films were respectively measured by using a UV spectrometer and an atomic force microscope. The surface morphology and imaging capabilities of photoresist film MLAs were respectively measured by using a scanning electron microscope and optical microscope. Finally, the photovoltaic performance of the silicon solar cell with the photoresist film MLAs was investigated, and the PCE value of the silicon solar cell improved from 11.53% for the sample without MLAs to 13.19% for the sample with the square MLAs and the PCE improvement is about 14.40%. All these results above show that the photoresist film MLAs can significantly improve the efficiency of silicon solar cells and have great application potential in the field of solar cells.