Fabrication of Rb2TeI6 thin films for stable, lead-free perovskite photodetector via dry-processed approach

In the vacancy-ordered double perovskite group, rubidium tellurium iodide is a rarely studied material. In this paper, we report the fabrication of Rb2TeI6 thin film via a dry-processed approach. The process includes the chemical vapor deposition of the RbI film, followed by a thermal annealing treatment in TeI4 vapor. The film has a tetragonal structure with good morphology, high absorption coefficient (> 105 cm-1 in the 280-620 nm wavelength range), and good stability in ambient air. A photodetector is fabricated by growing a 300 nm-thick Rb2TeI6 film on indium-doped tin oxide electrodes. The Rb2TeI6-based photodetector has 0.87 pA dark current at 5 V bias. Under 450 nm illumination, it shows 1.4 mA/W photoresponsivity, ap-proximately 1010 J photodetectivity, and 16.4 ms/19.2 ms response times with an excellent operational stability. This study not only presents an effective technique for fabricating the Rb2TeI6 perovskite thin film, but also shows its potential for photodetector application.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This paper reports a dry-processed approach for fabricating Rb2TeI6 thin film, a rarely studied material in the vacancy-ordered double perovskite group. The film exhibits a tetragonal structure with good morphology, high absorption coefficient, and good stability in ambient air. A photodetector based on the Rb2TeI6 thin film shows excellent photoresponsivity, photodetectivity, and response times, along with operational stability, indicating its potential for photodetector applications.