Tuning Band Tails in Mono- and Multilayered Transition-Metal Dichalcogenides: A Detailed Assessment and a Quick-Reference Guide

Transition-metal dichalcogenides (TMDs) are promising candidates for a wide variety of ultrascaled electronic, optoelectronic, and quantum-computing applications. The electronic density states exponentially decaying into the band gap (also known as tail) has strong impact on performance TMD In this work, tails various monolayer multilayer systems is predicted with density-functional-theory-based nonequilibrium Green's functions when placed several dielectric substrates such ${\mathrm{Hf}\mathrm{O}}_{2}$, ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}$, ${\mathrm{Si}\mathrm{O}}_{2}$, $h$-BN. Nonlocal scattering electrons polar optical phonons, charged impurities, remote phonons in materials included self-consistent Born approximation. found to critically depend layer thickness, temperature, doping concentration, particularly chosen substrate. underlying physical mechanisms studied high detail an analytical interpolation formula given provide quick reference Urbach parameters guide design work ${\mathrm{Mo}\mathrm{S}}_{2}$, ${\mathrm{WS}}_{2}$, ${\mathrm{WSe}}_{2}$.