Laser-engineered oxygen vacancies for improving the NO₂ sensing performance of SnO₂ nanowires

Methods for oxygen vacancy engineering usually require high-temperature heating processes, which are substantially time-consuming. Laser irradiation techniques are a viable alternative to conventional methods, as they enable room-temperature tuning of material functionality using a simple, swift, and inexpensive process. In this report, the effects of pulsed laser irradiation on the formation of oxygen vacancies and its positive relationship with the sensing performance of SnO₂ have been investigated. Based on density functional theory calculations, we suggest that the formation of laser-induced bridging oxygen defects and the resulting excess electrons on the SnO₂ surface change the surface orbital structures of the Sn atoms in a manner favorable for NO₂ adsorption, thus playing a key role in improving its sensing performance.