Efficient, broadband and wide-angle hot-electron transduction using metal-semiconductor hyperbolic metamaterials. (August 2016)

• Record Type: Journal Article
• Authors: Sakhdari, Maryam; Hajizadegan, Mehdi; Farhat, Mohamed; Chen, Pai-Yen
• Is Part Of: Nano energy. Volume 26(2016:Aug.)
• Page Start: 371
• Page End: 381
• Publication Date: 2016-08
• Subjects: Hot electrons -- Internal photoemission -- Sub-bandgap photovoltaics -- Photodetection -- Plasmonics -- Metamaterials; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2016.05.037
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Hot-electron devices are emerging as promising candidates for the transduction of optical radiation into electrical current, as they enable photodetection and solar/infrared energy harvesting at sub-bandgap wavelengths. Nevertheless, poor photoconversion quantum yields and low bandwidth pose fundamental challenges to fascinating applications of hot-electron optoelectronics. Based on a novel hyperbolic metamaterial (HMM) structure, we theoretically propose a vertically-integrated hot-electron device that can efficiently couple plasmonic excitations into electron flows, with an external quantum efficiency approaching the physical limit. Further, this metamaterial-based device can have a broadband and omnidirectional response at infrared and visible wavelengths. We believe that these findings may shed some light on designing practical devices for energy-efficient photodetection and energy harvesting beyond the bandgap spectral limit. Graphical abstract: Highlights: A "stereo" hot-electron device based on hyperbolic metamaterials is presented. Results show broadband and omnidirectional enhancement in external quantum efficiency. Results show great potential in energy-efficient, sub-bandgap photodetectors, spectrometers, and plasmonic sensors. Applicability of hot-electron devices to energy harvesting is evaluated.