The development of high-performance gas sensing materials is one of the development trends of new gas sensor technology. In this work, in order to predict the gas-sensitive characteristics of HfSe₂ and its potential as a gas-sensitive material, the interactions of nonmetallic element (O, S, Te) doped HfSe₂ monolayer and small molecules (NH₃ and O₃) have been studied by first-principles based on density functional theory. The results show that the adsorption of NH₃ and O₃ on pristine HfSe₂ monolayer is weak, and the adsorption strength can be significantly improved by doping O. And O-HfSe₂ is chemical adsorption to O₃ with large adsorption energy and transfer charge, and the band gap of OHfSe₂ disappears after adsorbing O₃, indicating that the adsorption of O₃ has a significant effect on the electrical properties of the substrate. These mean that O₃ is difficult to recover from the substrate surface, thus preventing O-HfSe₂ from developing into a sensitive material for O₃ detection. After doping S, the charge transfers and adsorption strength to NH₃ are the largest, but it is still small. So, the strain effect on the S-HfSe₂/NH₃ adsorption system is also studied. The results indicate that the adsorption strength of S-HfSe₂ to NH₃ can be enhanced by stretching S-HfSe₂ along x-axis. After absorbing NH₃, the conductivity of x-axis strained S-HfSe₂ changes, which suggest its sensitivity. And the predicted recovery times of S-HfSe₂ surfaces with ε_x=4%, 6% and 8% are 0.027 s, 1.153 s and 102.467 s, respectively, which suggests that the S-HfSe₂ monolayer has the potential to be developed as a sensitive material for NH₃ detection. These adsorption mechanism studies can also serve as a theoretical foundation for the experimental design of gas-sensing materials.

高性能气敏材料的开发是新型气敏技术的发展趋势之一。在这项工作中，为了预测 HfSe ₂的气敏特性及其作为气敏材料的潜力，非金属元素（O、S、Te）掺杂的 HfSe ₂单层与小分子（NH ₃和 O ₃ ) 已经通过基于密度泛函理论的第一性原理进行了研究。结果表明，NH ₃和O ₃在原始HfSe ₂单分子层上的吸附较弱，通过掺杂O可以显着提高吸附强度。而O-HfSe _{2是对O 3}的化学吸附。具有较大的吸附能和转移电荷，吸附O ₃后O HfSe ₂的带隙消失，说明O 3 的吸附对_基体的电学性能有显着影响。这意味着O ₃难以从基板表面回收，从而阻止了O-HfSe ₂发展成为O ₃检测的敏感材料。_{掺杂S后，对NH 3}的电荷转移和吸附强度最大，但仍较小。因此，应变对 S-HfSe ₂ /NH _3的影响吸附系统也进行了研究。结果表明，通过沿x轴拉伸S-HfSe ₂可以增强S-HfSe ₂对NH _{3的吸附强度。}吸收NH _3后，x轴应变S-HfSe ₂的电导率发生变化，这表明其敏感性。ε _x =4%、6%和8%的S-HfSe ₂表面的预测恢复时间分别为0.027 s、1.153 s和102.467 s，这表明S-HfSe ₂单层具有发展潜力作为 NH _{3的敏感材料}检测。这些吸附机理研究也可以作为气敏材料实验设计的理论基础。