Simple synthesis of ultra-high quality In2S3 thin films on InAs substrates

We report a simple and reliable technique to synthesize high-quality In2S3 films on InAs substrates by using thermal sulfurization in a hot-wall tube furnace. X-ray diffraction and energy dispersive X-ray spectroscopy data confirmed that the synthesized films were cubic β-In2S3 or tetragonal β-In2S3, depending on growth conditions. Field emission scanning electron microscopy analysis and Raman spectroscopy showed that the In2S3 films are of remarkable crystal quality. Especially, by optimizing the growth conditions, we have grown an extremely high-quality tetragonal β-In2S3 thin film firmly remained on the InAs substrate, for the first time.