Anisotropic electrolyte electroreflectance study of rhenium-doped MoS2

Anisotropy of rhenium-doped MoS2 parallel and perpendicular to the c-axis ( k parallel to c and k perpendicular to c) was studied using electrolyte ele ctroreflectance (EER) measurements over an energy range from 1.75 eV to 4.5 eV. The measurements for k perpendicular to c were made possible by the th icker samples of MoS2 available through introducing a small concentration o f rhenium during growth. The excitonic transitions A and B for both k perpe ndicular to c and k parallel to c configurations showed different degrees o f red shift compared with that of the undoped sample. It is found that rhen ium which is present as an intentionally doped impurity plays an important role in affecting the observed differences.