Large-area, thermally-sulfurized WS₂ thin films: control of growth direction and use as a substrate for GaN epitaxy

Abstract

We present a detailed study of the influence of metal seed thickness, amount of sulfur, sulfurization time and temperature on the morphology of large-area WS 2 thin films prepared by sulfurization of electron-beam evaporated tungsten layers. We show how preferably horizontally or vertically oriented films can be achieved. The WS 2 films with horizontal morphology were used as nearly lattice-matched substrates for the growth of GaN layers by MOVPE. While epitaxial films of GaN could be demonstrated, the thin-film WS 2 layers show a enhanced propensity for degradation in the strongly reducing and high-temperature MOVPE growth environment.

Continuous Single‐Crystalline GaN Film Grown on WS2‐Glass Wafer

“…further showed that thermally sulfurized WS 2 is also a proper buffer layer for GaN growth. [ 11f,14 ] Yu et al. reported that, besides transfer, directly growing WS 2 on GaN is also a promising strategy to fabricate WS 2 /GaN p‐n junction.…”