Enhanced hot electron generation on $MAPbI_3$ modified plasmonic nanodiode

Abstract

Hot electron based solar cells that collect highly energetic hot electrons as a photocurrent has been widely studied, because they can exceed the maximum efficiency of standard solar cells. However, the relaxation of hot electrons occurs so fast that it is hard to collect them efficiently, which is major challenge for practical use. For this reason, hybrid lead halide perovskite ($MAPbI_3$) has been emerged as a strong candidate for light absorbers in hot electron solar cells because it shows much longer lifetime and diffusion length of hot electrons than other semiconductors. However, there is no attempt to utilize such outstanding hot electron properties for photovoltaics. Therefore, we investigated $MAPbI_3$ modified plasmonic nanodiode to improve hot electron generation for effective hot electron capture. With photocurrent and incident photon to current conversion efficiency measurement, we confirmed enhanced photo-conversion efficiency. Also, based on pump-probe experiment, we showed elongated lifetime of hot electrons in perovskite with plasmonic structure. Therefore, we conclude that plasmonic effect can affect positively on both hot electron generation and lifetime. These findings could suggest novel method to amplify hot electron generation that can contribute to design efficient hot carrier solar cell.