Boosting Optical Current in Amorphous Silicon Solar Cells Using Multi-layer Bimetallic Plasmonic Nano-ring Structures

Incorporating multi-layer bimetallic plasmonic nano-ring structures into amorphous silicon solar cells can effectively enhance the optical current by manipulating light absorption and trapping. Improving the photocurrent density in amorphous silicon (a-Si) solar cells is essential for enhancing their efficiency and competitiveness in thin-film photovoltaic applications. This study investigates the impact of multi-layer plasmonic nano-ring structures, composed of alternating layers of aluminum (Al) and nickel (Ni), on the optical current of a-Si solar cells. Using various nano-ring configurations for a cell with periods of 200 nm, 300 nm, and 400 nm, the effect of different layering sequences on photocurrent density were analyzed. Results indicate that the inclusion of nano-rings significantly boosts photocurrent density and higher layer counts yielding the greatest improvements. For instance, the Al/Ni/Al/Ni/Al/Ni/Al configuration at 200 nm achieved a maximum photocurrent density of 23.88 mA/cm², a notable increase from the baseline value of 16.65 mA/cm² observed without nano-rings. These findings highlight the role of tailored plasmonic nano-ring structures in enhancing light absorption and charge generation, providing a promising approach for optimizing a-Si solar cell performance through structural design innovations.