Simultaneous Harvesting of Bipolar Plasmonic Hot Carriers for Boosting Photoconductivity in Ag Nanoprism-Coupled Lateral Si p-n Junction.

Plasmonic hot carriers have garnered considerable attention in photovoltaics and photocatalysis, yet their full potential is limited by the challenge of harvesting both positive and negative polarity hot carriers at the same time. Here, an unprecedented plasmonic hot carrier device capable of extracting both types of hot carriers simultaneously is demonstrated. This scheme involves generating and harnessing plasmonic hot electrons and holes concurrently using a lateral Si p-n junction diode coupled to Ag nanoprisms. The experimental and numerical results jointly reveal precise control of the generation and injection of plasmonic hot carriers, stemming from differing injection probabilities of each type of hot carrier into the substrates. It is shown that the bipolar plasmonic photodetector exhibits outstanding performance compared to plasmonic devices utilizing single-polarity hot carriers, attributed to the simultaneous participation of plasmonic hot carriers in the photoconductivity nature of the diode. It is believed that this strategy of harnessing bipolar hot carriers will pave the way for the rational design of future plasmonic applications by providing significantly improved photoconductivity and flexible utilization of hot carriers.