Excitons in VI B Transition Metal Dichalcogenides

Abstract

The magnetic circular dichroism (MCD) have been studied for A, B excitons in MoS 2 , WS 2 , MoSe 2 and WSe 2 together with A', B' excitons in the diselenides. The effective g -values are obtained as nearly -3 for A, B and between -3 and -5 for A', B'. By reference to band calculations and the piezo-reflectance study, the experimental results lead to the conclusion that the A, B excitons correspond to transitions from d z 2 band to d x y and d x 2 - y 2 bands at the \(\varGamma\) point and the A', B'excitons from p band to d x z and d y z bands at the same point.