LAUSR

Monolayer transition metal dichalcogenides (TMDS) are highly luminescent materials despite being sub-nanometer thick. This is due to the ultrashort ( cQ) as the generalized lower bound for allowed radiative recombination. A self-consistent methodology, which becomes crucial upon inclusion of large radiative broadening in the exciton band, is proposed to segregate the radiative and the nonradiative components of the homogeneous exciton linewidth. We estimate a fundamental radiative linewidth of 1.54 +/- 0.17 meV, owing purely to finite radiative lifetime in the absence of nonradiative dephasing processes. As a direct consequence of the large radiative limit, we find a surprisingly large (similar to 0.27 meV) linewidth broadening due to zero-point energy of acoustic phonons. This obscures the precise experimental determination of the intrinsic radiative linewidth and sets a fundamental limit on the nonradiative linewidth broadening at T = 0 K.