Hybrid k center dot p tight-binding model for intersubband optics in atomically thin InSe films

摘要

We propose atomic films of n-doped gamma-InSe as a platform for intersubband optics in the infrared and far-infrared range, coupled to out-of-plane polarized light. Depending on the film thickness (number of layers) and the amount of n-doping of the InSe film, these transitions span from similar to 0.7 eV for bilayer to similar to 0.05 eV for 15-layer InSe. We use a hybrid k center dot p theory and tight-binding model, fully parametrized using density-functional theory, to predict their oscillator strengths and thermal linewidths at room temperature.