Plasmonic-enabled nanostructures for designing the next generation of silicon photodetectors: Trends, engineering and opportunities

The escalating demand for silicon photodetectors in diverse applications, ranging from sensing to imaging and communications, has prompted the exploration of innovative enhancements. This review delves into recent strides in augmenting the performance of silicon photodetectors through the integration of plasmonic nanostructures, specifically silver nanowires (AgNWs). The synergy between AgNWs and silicon photodetectors proves instrumental in elevating their functionality by amplifying light absorption and facilitating efficient charge transfer. The review commences with an in-depth exploration of silicon photodetectors, encompassing their fundamental principles, performance metrics, and versatile applications. Subsequently, it delves into the intricacies of plasmonic enhancement mechanisms employed in photodetectors, incorporating various nanostructures such as quantum dots, nanowires, and nanorods. AgNWs enhance silicon photodetector efficiency by exploiting strongly localized surface plasmon resonances, concentrating incident light, and contextualizing the discussion. Further, it elucidates standard synthesis techniques for AgNWs, emphasizing the impact of their morphology on optical properties. A comprehensive theoretical framework elucidates the nuanced physics underlying plasmonic interactions at the nanoscale. The synthesis techniques set the stage for detailing strategies for integrating AgNW networks with silicon, facilitating the fabrication of high-performance Schottky junction and lateral photovoltaic effect photodetectors. Compared to their bare silicon counterparts, these integrated devices exhibit substantially higher responsiveness and detectability. It highlights the importance of optimizing AgNW coverage density, addressing contact resistance, and ensuring precise alignment for maximum light trapping. Through adept integration of tailored AgNW nanostructures, silicon photodetectors provide new opportunities to develop next-generation photonic devices.