Study of metamaterial-based light absorber and self-powered photodetector

Abstract

Metamaterial absorber with the unexpected capability for harvesting electromagnetic energy has been regarded as a potential route for various applications In this study we presented the simple absorber structure through the involvement of hybrid dual-resonators that could allow the wideband light absorption covered from 450 nm to 600 nm with average absorptivity above 95% In addition this research used the high photosensitivity characteristics of carbon quantum dots combined with silicon to create a unique nanoparticle metamaterial light absorber The average reflectance results reached 13% The IPCE analysis confirmed that the carbon quantum dot film with a thickness of 65 nm has the best result of 43 2% In terms of device analysis relationship between photocurrent and the involved power intensities of the incident light were fitted with power law Under the 580 nm light source the best responsivity and detectivity of the device reach 0 628 mA/W and 9 36 x 1012 Jones The normalized photocurrent to dark current ratio and equivalent noise power reaches 2 25 x 107 W-1 and 1 52 x 10-13 W·cm / Hz1/2 The figures of merit are measured under zero bias which shows the self-powered ability of the photodetector In line with reliability test the responsivity of the device drops only 4 7% and 1% under a load of 200g and the temperature at 115°C The on-off transient switching response of the photodetector was tested for 2000 cycles The results verified that the stable and reliable operation capability of device performance that could be potential for practical use

Date of Award	2020
Original language	English
Supervisor	Chia-Yun Chen (Supervisor)