Sulphur-Passivated GaAs Investigation Using High Resolution X-Ray Diffractometry

Abstract

The growth of a MoS2 layer on a GaAs(111) substrate produces a highly strained interface layer, which relaxes via generation of dislocations. Using high-resolution X-ray diffractometry in the triple-axis scheme we investigated this interfacial layer, which results from dipping an epi-ready GaAs wafer in ammonium sulphide, followed by deposition of an RF-sputtered MoS2 layer. The dislocation density revealed from the measurements is of the 106 cm-2. This suggests that high efficiency (~20%) MoS2/GaAs heterojunction photovoltaic devices are feasible.