Long-Persistent Photoconductivity in Transistor Structures Made from Thin ZrS₃-Films

authored by

Lars Thole, Asem Ben Kalefa, Christopher Belke, Sonja Locmelis, Lina Bockhorn, Peter Behrens, Rolf J. Haug

Abstract

In the search for two-dimensional (2D) materials, transition-metal trichalcogenides (TMTCs) have emerged as promising candidates for optoelectronic applications. Here, we show a very long-lasting persistent photoconductivity (PPC) over several hours in thin films of the TMTC zirconium trisulfide (ZrS₃) at room temperature when illuminated with a 470 nm LED. ZrS₃ crystals were grown using chemical vapor transport. UV-vis spectroscopy showed an indirect band gap of 1.81 eV and an Urbach energy of 83 meV, indicating that the system has a large number of defects. Transistor measurements on thin layers with thicknesses varying between 19 and 50 nm showed ZrS₃ to be an n-type semiconductor. The conductivity increases under illumination, and it only reaches the original state several hours after switching off the illumination. This PPC can be described by using a stretched exponential function. On top of that, the sum of three exponential functions with tree different relaxation times fits the observed PPC nearly equally well. This shows that three processes dominate the relaxation. The three observed processes can be differentiated with respect to their origin by their dependence on the thickness of the thin layers.

Organisation(s)

Institute of Solid State Physics
Institute of Inorganic Chemistry
Laboratory of Nano and Quantum Engineering
Faculty of Mathematics and Physics
QuantumFrontiers
PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines

Type

Article

Journal

ACS Applied Electronic Materials

Volume

5

Pages

6286–6291

No. of pages

6

Publication date

28.11.2023

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials, Materials Chemistry, Electrochemistry

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

https://doi.org/10.1021/acsaelm.3c01163 (Access: Open)