Modification of lanthanum-doped tin oxide thin films by 532 nm laser annealing for H ₂ S gas sensors

In this study, lanthanum-doped tin oxide (SnO 2 : La) thin films were fabricated via RF magnetron sputtering and subsequently annealed using a 532[Formula: see text]nm laser. The effects of laser power on the films’ structural, morphological, and chemical properties were systematically investigated. Experimental results demonstrated that the sensor annealed at an optimal power of 5[Formula: see text]W achieved a refined nanocrystalline structure and a significant increase in surface oxygen vacancies (from 21.42% to 40.20%), which are crucial for gas-sensing reactions. At an operating temperature of [Formula: see text]C, the optimized SnO 2 : La sensor exhibited a high response of 288% toward 1[Formula: see text]ppm H 2 S, along with excellent selectivity and reproducibility. These findings highlight the effectiveness of 532[Formula: see text]nm laser annealing in modulating the surface defects and enhancing the sensing performance of metal-oxide-based gas sensors for toxic gas detection.