Tunable band gap and optical properties of surface functionalized Sc2C monolayer

Using the density functional theory, we have investigated the electronic and optical properties of two-dimensional Sc2C monolayer with OH, F, or O chemical groups. The electronic structures reveal that the functionalized Sc2C monolayers are semiconductors with a band gap of 0.44–1.55 eV. The band gap dependent optical parameters, like dielectric function, absorption coefficients, reflectivity, loss function, and refraction index were also calculated for photon energy up to 20 eV. At the low-energy region, each optical parameter shifts to red, and the peak increases obviously with the increase of the energy gap. Consequently, Sc2C monolayer with a tunable band gap by changing the type of surface chemical groups is a promising 2D material for optoelectronic devices.