Growth and optical studies of tungsten disulphide single crystals doped with gold

Tungsten disulphide single crystals doped with gold (WS2:Au) have been grown by the chemical vapor transport method using iodine as a transporting agent. The structure of the materials was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and Raman measurements. The doping effects of the materials are characterized by surface photovoltage (SPV) and piezoreflectance (PzR) measurements. The SPV spectrum reveals an impurity level located below the A exciton. The direct band-edge excitonic transition energies for WS2:Au show redshifts and the broadening parameters of the excitonic transition features increase due to impurity scattering.