Selective growth of wide band gap atomically thin Sb2O3 inorganic molecular crystal on WS2

Abstract

Heterostructures combined by different individual two-dimensional (2D) materials are essential building blocks to realize unique electronic, optoelectronic properties and multifunctional applications. To date, the direct growth of 2D/2D atomic van der Waals heterostructures (vdWHs) have been extensively investigated. However, the heterostructures from 2D inorganic molecular crystals and atomic crystals have been rarely reported. Here we report two-step direct epitaxial growth of the inorganic molecular-atomic Sb2O3/WS2 vdWHs. The thickness of Sb2O3 nanosheets on WS2 nanosheets can be tuned by variable growth temperatures. Oriented growth behavior of Sb2O3 on WS2 was determined through statistics. Optical images, Raman spectra, Raman mappings and selected-area electron diffraction (SAED), etc., reveal that Sb2O3/WS2 heterostructures are vertically stacked with high crystal quality. Electrical transport measurements demonstrate that the heterotransistors based on the heterostructures possess high current on/off ratio of 5 × 105, obvious gate-tunable and current rectification output characteristics. Optoelectronic characterizations show that the heterostructures have a clear photoresponse with high responsivity of 16.4 A/W. The growth of vdWHs from 2D inorganic molecular-atomic crystals may open up new opportunities in 2D functional electronics and optoelectronics.