A comparative study of biaxial strain modulated electronic structure of MSe2 (M = W, Mo) monolayer

In this work, we have compared the biaxial strain-induced variations in the band structures of MSe
2
(
$\mathrm{M}= \mathrm{W}$
, Mo) monolayers using density functional theory (DFT) calculations. We determined that the critical biaxial strain range within the bandgap of MSe
2
ML remains direct upon application of
$\varepsilon$
from +6% to −6%. By linear fitting the variation of tensile strain
$(\varepsilon > 0)$
with K-K (A peak) and
$\Gamma-\mathrm{K}$
(I peak) energy gaps, we have calculated a rate of red-shift in the bandgap of MSe
2
ML. Also, we have compared the rate of bandgap tunability of MSe
2
ML for all three possible bandgap transition routes, i. e., K -
$\Sigma_{\min}$
, K-K, and
$\Gamma-\mathrm{K}$
energy gaps. We strongly believe that this analysis and insights will help interpret experiments and modeling based on MSe
2
ML for future optoelectronic device applications.