Work

Multilayer W-doped vanadium dioxide thermal sensors with extended operation region

Year: 2025

Type: article

Abstract: Bolometers rely upon the temperature coefficient of resistance (TCR) of their underpinning sensing layer to detect infrared radiation. Vanadium dioxide (VO 2 ) exhibits a very large, but abrupt TCR associated with its monoclinic to rutile phase transition. W-doping of VO 2 lowers and broadens its transition temperature, and by combining multiple discrete W:VO 2 layers, a sensing layer can be created with an extended temperature operation region. Herein, we report such a multilayer W:VO 2 thin film by atomic layer deposition (ALD). The film displays an average TCR of −9.5 (±3.5) %K −1 from 30°C to 60°C. A sensing layer consisting of 10 individual W:VO 2 layers is simulated with a multi-objective genetic algorithm (MOGA) for maximum average TCR (μ) and minimum variation (σ) across an extended target temperature range producing an optimized layer structure at max ( | μ | − σ ) with average TCR response of −6.7 (±0.9) %K −1 from 20°C to 70°C. This work highlights the potential for the broader application of uncooled bolometers. • W-doped VO 2 resistivity response model based on experimental ALD film data’ • Experimental thermal sensing performance of multi-layer W:VO 2 with high TCR • Multi-objective genetic algorithm optimization of multi-layer W:VO 2 between 20°C and 70°C • Performance optimum found for multilayer with flat TCR over the wide temperature range Physics; Optics; Materials science

Source: iScience

DOI: 10.1016/j.isci.2025.112528