Electronic structures, mechanical properties and carrier mobilities of π-conjugated X(X = Ni, Pd, Pt) bis(dithiolene) nanosheets: Theoretical predictions

Using first-principles calculations, we have investigated the electronic structures, mechanical properties and carriers mobilities of π-conjugated X(X = Ni, Pd, Pt) bis(dithiolene) nanosheets (XDts). Firstly, Gaussian-Perdue-Burke-Ernzerhof (Gau-PBE) functional band structures of XDts have been calculated. XDts are narrow band gap semiconductors, and the band gaps are 0.392 eV (NiDt), 0.082 eV (PdDt), 0.336 eV (PtDt), respectively. Secondly, we present a method to calculate the elastic modulus of 2D material in arbitrary direction. Using this method, we predict that the elastic moduli of XDts are isotropic, and the Young's moduli of those nanosheets are 87 GPa (NiDt), 78.2 GPa (PdDt), and 86.5 GPa (PtDt), respectively, which are much softer than graphene due to their large porosity. Thirdly, we have calculated the mobilities of XDts by deformation potential method. The electron mobilities of XDts are higher than 2.0 × 103 cm2 V−1 s−1. In particular, the electron mobility of PdDt reaches 14.86 × 103 cm2 V−1 s−1. Our results show that XDts have a wide range of potential applications in nano devices.