High-resolution remote thermography using luminescent low-dimensional tin-halide perovskites

TL;DR

This paper introduces a novel thermography method using low-dimensional tin-halide perovskites with temperature-dependent photoluminescence lifetimes, enabling high-resolution thermal imaging with tunable temperature sensitivity.

Contribution

It demonstrates the use of low-dimensional tin-halide perovskites' PL lifetime dependence for precise thermal imaging and develops a cost-effective fluorescence lifetime imaging system.

Findings

PL lifetime varies over several orders of magnitude with temperature

Thermal imaging resolution of 0.05°C achieved

Temperature sensitivity range is tunable from -100°C to 110°C

Abstract

While metal-halide perovskites have recently revolutionized research in optoelectronics through a unique combination of performance and synthetic simplicity, their low-dimensional counterparts can further expand the field with hitherto unknown and practically useful optical functionalities. In this context, we present the strong temperature dependence of the photoluminescence (PL) lifetime of low-dimensional, perovskite-like tin-halides, and apply this property to thermal imaging with a high precision of 0.05 {\deg}C. The PL lifetimes are governed by the heat-assisted de-trapping of self-trapped excitons, and their values can be varied over several orders of magnitude by adjusting the temperature (up to 20 ns {\deg}C-1). Typically, this sensitive range spans up to one hundred centigrade, and it is both compound-specific and shown to be compositionally and structurally tunable from -100 to 110 {\deg} C going from [C(NH2)3]2SnBr4 to Cs4SnBr6 and (C4N2H14I)4SnI6. Finally, through the innovative implementation of cost-effective hardware for fluorescence lifetime imaging (FLI), based on time-of-flight (ToF) technology, these novel thermoluminophores have been used to record thermographic videos with high spatial and thermal resolution.