Fabrication of BaZrS3 chalcogenide perovskite thin films for optoelectronics

TL;DR

This study demonstrates the successful fabrication of BaZrS3 thin films with promising optoelectronic properties, including high absorption and tunable mobility, advancing its potential for applications like photodetectors and LEDs.

Contribution

First report of BaZrS3 thin films fabricated via sulfurization of oxide films, revealing key optoelectronic properties relevant for device applications.

Findings

BaZrS3 thin films are n-type with high carrier densities.

Mobility varies with processing temperature, reaching up to 13.7 cm^2/Vs.

Absorption coefficient exceeds 10^5 cm^-1 at >1.97 eV.

Abstract

BaZrS3 is a prototypical chalcogenide perovskite, an emerging class of unconventional semiconductor. Recent results on powder samples reveal that it is a material with a direct band gap of 1.7-1.8 eV, a very strong light-matter interaction, and a high chemical stability. However, many of the fundamental properties are unknown, hindering the ability to apply BaZrS3 for optoelectronics. Here we report the fabrication of BaZrS3 thin films, by sulfurization of oxide films deposited by pulsed laser deposition. We show that these films are n-type with carrier densities in the range of 10^19-10^20 cm^-3. Depending on the processing temperature, the Hall mobility ranges from 2.1 to 13.7 cm^2/Vs. The absorption coefficient is > 10^5 cm-1 at photon energy > 1.97 eV. Temperature dependent conductivity measurements suggest shallow donor levels. These results assure that BaZrS3 is a promising candidate for optoelectronics such as photodetectors, photovoltaics, and light emitting diodes.