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 a series 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 a high efficiency (~20%) MoS₂/GaAs heterojunction photovoltaic devices are feasible.