Growth of centimeter-scale single crystal MoO3 ribbons for high performance ultraviolet photodetectors
Di Wu, Dianyu Qi, Jidong Liu, Zixuan Wang, Qiaoyan Hao, Guo Hong, Liu Fei, Fangping Ouyang, Wenjing Zhang
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.