Date of Award

December 2021

Degree Type

Thesis

Degree Name

Master of Science

Department

Engineering

First Advisor

Prasenjit Guptasarma

Committee Members

George Hanson, Habib Tabatabai

Keywords

Cd3As2, Infrared photodetectors, Photo-thermo-voltaic effect, Seebeck effect

Abstract

In this thesis, we engineered a fast response high bandwidth self-powered infrared photodetector based on optically induced Seebeck effect in Cd3As2 operating at room temperature. The metal-semimetal-metal device was subject to transient photo-response tests using high-frequency lock-in modulation techniques. Our photodetector demonstrates a Seebeck voltage under the off-center illumination of a laser with the wavelength of 1064 nm, due to a temperature gradient. The photocurrent is readily registered at a modulation frequency of 6 kHz and further analysis indicates the sensor intrinsic bandwidth is predicted to approach the terahertz range. The responsivity of the sensor is 0.27 mA/W at room temperature and the photocurrent is found to be dependent on the modulation frequency and the optical power. Our study reveals that Cd3As2 is a promising candidate for a fast response, high bandwidth spectrally broad device applications in optoelectronics.

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