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Hot-electron photocurrent detection of near-infrared light based on ZnO

Authors :
Yun Hou
Xiao-bo Du
Zhi-Gang Mei
Aihua Tang
Liang Huili
Publication Year :
2021

Abstract

We demonstrate an unconventional near-infrared photodetector fabricated from a ZnO chip with a metallic subwavelength grating structure as a contact and optical window, which harvests hot electrons generated by plasmonic resonances introduced by incident light. The grating structure has a strong selection of the polarization of incident light, meaning that the detector is naturally polarization-sensitive. In our device, the polarization extinction ratio is as high as 64:1, much higher than that relying on crystal orientations. Since the photoresponse is introduced by plasmonic resonance, a narrow photoresponse spectrum with a linewidth of 32.1 nm at 1.201 μm is obtained. By simply changing the grating period, the spectral position can be tailored freely within the near-infrared region, i.e., wavelength-selective. Such a spectral response is not likely to be realized with conventional semiconductor photodetectors, which depend on the band edge absorption. We propose a modified Fowler's model, which well explains the line shape of photoresponse spectra of such devices.

Details

Language :
English
Database :
OpenAIRE
Accession number :
edsair.doi.dedup.....4972a9faf83ade421ce7fd5e684ce1dc