Enhanced ammonia gas sensing response of Al-hyperdoped black silicon sensor at room temperature

Abstract

Al-hyperdoped black silicon (Al-BSi) is prepared by femtosecond laser-assisted chemical etching, and the material surface was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The gas sensing performance of the Al-BSi sensor to NH₃ at room temperature was systematically studied, and the sensor has the characteristics of high responsivity, fast response speed, good selectivity, and long-term durability. The NH₃ gas sensing ability is effectively enhanced by the introduction of Al dopants, and the responsivity is more than 1.76 times higher than that without Al hyperdoping. In addition, the band structure of the Al-hyperdoped layer was calculated using first principles, and the potential mechanism of the enhanced responsivity of the Al-BSi sensor was proposed. These results are helpful for the development of high-precision and high-reliability gas sensors based on Al-BSi, opening up potential applications in different fields such as environmental monitoring and industrial safety.