Magneto-excitons in large area CVD grown monolayer MoS$_{2}$ and   MoSe$_{2}$ on sapphire
  Magneto transmission spectroscopy was employed to study the valley Zeeman effect in large-area monolayer MoS$_{2}$ and MoSe$_{2}$. The extracted values of the valley g-factors for both A- and B-exciton were found be similar with $g_v \simeq -4.5$. The samples are expected to be strained due to the CVD growth on sapphire at high temperature ($700^\circ$C). However, the estimated strain, which is maximum at low temperature, is only $\simeq 0.2\%$. Theoretical considerations suggest that the strain is too small to significantly influence the electronic properties. This is confirmed by the measured value of valley g-factor, and the measured temperature dependence of the band gap, which are almost identical for CVD and mechanically exfoliated MoS$_2$. 
A. A. Mitioglu, K. Galkowski, A. Surrente, L. Klopotowski, D.   Dumcenco, A. Kis, D. K. Maude, and P. Plochocka
cond-mat.mes-hall