Growth of centimeter-scale single crystal MoO3 ribbons for high performance ultraviolet photodetectors

Abstract

Molybdenum oxides have attracted much interest due to their unique electronic properties. Here, we report a convenient and efficient method to synthesize centimeter-scale single crystal of MoO3 ribbons through an atmospheric pressure physical vapor deposition approach. Optical microscopy, atomic force microscopy, high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction, and x-ray diffraction measurements reveal that the MoO3 ribbons grow along the MoO3⟨100⟩ direction and the top surface is MoO3(010) plane. Raman spectroscopy, x-ray photoelectron spectroscopy, and cross-sectional HRTEM results disclose that the surface of MoO3 ribbons can be transformed from MoO3 to MoO2 through H2 annealing treatment forming MoO2/MoO3 heterostructure. We found that the conductance and ultraviolet photoresponsivity of the MoO3 ribbons can be improved by ∼11 and ∼5 orders of magnitude, respectively, after H2 annealing treatment, which will be helpful for the applications of MoO3 in the optoelectronic field.