标题：Strong and highlyasymmetrical optical absorption in conformal metal-semiconductor-metal gratingsystem for plasmonic hot-electron photodetection application
作者：Kai Wu, Yaohui Zhan, Cheng Zhang, Shaolong Wu, and XiaofengLi*
We propose an architecture of conformalmetal-semiconductor-metal (MSM) device for hot-electron photodetection byasymmetrical alignment of the semiconductor barrier relative to the Fermi levelof metals and strong energy localization through plasmonic resonances. Comparedwith the conventional grating design, the multi-layered grating system underconformal configuration is demonstrated to possess both optical and electricaladvantages for high-sensitivity hot-electron photodetection. Finite-elementsimulation reveals that a strong and highly asymmetrical optical absorption(top metal absorption >99%) can be realized under such a conformalarrangement. An analytical probability-based electrical simulation verifies thestrong unidirectional photocurrent, by taking advantage of the extremely highnet absorption and a low metal/semiconductor barrier height, and predicts thatthe corresponding photoresponsivity can be ~3 times of that based on theconventional grating design in metal-insulator-metal (MIM) configuration.