Single-layer PtSe₂ adsorbed with non-metallic atoms: geometrical, mechanical, electronic and optical properties and...

Recently, single-layer PtSe₂, possessing high carrier mobility and optical response, has been successfully fabricated. To further expand its application scope and find new physics, in this work, we functionalized it via the adsorption of non-metallic atoms X (X = H, B, C, N, O, and F) to form hybrid systems X-PtSe₂, and their geometrical, mechanical, electronic, and optical properties as well as strain tuning effects were studied deeply. Calculations show that the energy stability of X-PtSe₂ systems is significantly enhanced, and they also hold higher thermal and mechanical stability. Particularly, X-PtSe₂ systems present excellent in-plane tenacity and out-of plane stiffness against deformations, which make them more applicable for designing nanodevices. Intrinsic PtSe₂ is a semiconductor, while the X-PtSe₂ system can be a band-gap narrowed semiconductor or metal, thus expanding the application scope for PtSe₂, and the odd-even effect of electronic phase variation related to the atomic number is found. Besides, the wavelength range of optical adsorption is increased in X-PtSe₂ systems, implying that its optical response region is wide, providing more options for developing optoelectronic devices. Moreover, it is shown that strain can flexibly tune the electronic property of X-PtSe₂ systems, especially enhancing the optical absorption ability substantially, beneficial for their applications in solar devices.