Broadband photodetection using one-step CVD-fabricated MoS(2)/MoO(2) microflower/microfiber heterostructures

Molybdenum disulfide (MoS(2)) has been combined so far with other photodetecting semiconductors as an enhancing agent owing to its optical and electronic properties. Existing approaches demonstrated MoS(2)-incorporated photodetector devices using complex and costly fabrication processes. Here, we report on simplified one-step on the chemical vapor deposition (CVD) based synthesis of a unique microfiber/microflower MoS(2)-based heterostructure formed by capturing MoO(2) intermediate material during the CVD process. This particular morphology engenders a material chemical and electronic interplay exalting the heterostructure absorption up to ~ 98% over a large spectral range between 200 and 1500 nm. An arsenal of characterization methods were used to elucidate the properties of these novel heterostructures including Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectrometry, high-resolution transmission and scanning electron microscopies, and Kelvin probe force microscopy. Our findings revealed that the MoS(2) and the MoO(2) crystallize in the hexagonal and monoclinic lattices, respectively. The integration of the MoS(2)/MoO(2) heterostructures into functional photodetectors revealed a strong photoresponse under both standard sun illumination AM1.5G and blue light excitation at 450 nm. Responsivity and detectivity values as high as 0.75 mA W(−1) and 1.45 × 10(7) Jones, respectively, were obtained with the lowest light intensity of 20 mW cm(−2) at only 1 V bias. These results demonstrate the high performances achieved by the unique MoS(2)/MoO(2) heterostructure for broadband light harvesting and pave the way for their adoption in photodetection applications.