Photocapacitive light sensor based on metal-YMnO3-insulator-semiconductor structures


Photocapacitive light sensor based on metal-YMnO3-insulator-semiconductor structures

Bogusz, A.; Choudhary, O. S.; Skorupa, I.; Bürger, D.; Lawerenz, A.; Lei, Y.; Zeng, H.; Abendroth, B.; Stäcker, H.; Schmidt, O. G.; Schmidt, H.

Technology of light sensors, due to the wide range of applications, is a dynamically developing branch of both, science and industry. This work presents a novel concept of photodetectors based on a metal-ferroelectric-insulator-semiconductor, a structure which has not been explored yet in the field of photodetectors. Functionality of the presented light sensor exploits the effect of ferroelectric polarization, charge trapping and photocapacitive phenomena. This is accomplished by an interplay between polarization alignment, subsequent charge distribution and charge trapping processes under given illumination condition and gate voltage. Change of capacitance serves as a read out parameter indicating the wavelength and intensity of illuminating light. The operational principle of the proposed photocapacitive light sensor is demonstrated in terms of capacitance-voltage and capacitance-time characteristics of an Al/YMnO3/SiNx/p-Si structure exposed to green, red, and near infrared light. Obtained results are discussed in the terms of optical properties of YMnO3 and SiNx layers contributing to the performance of photodetectors. Presented novel concept of light sensing might serve as the basis for the development of more advanced photodetectors.

Keywords: light; sensor; photodetector; YMnO₃; photocapacitance

Permalink: https://www.hzdr.de/publications/Publ-22264
Publ.-Id: 22264