Abstract
A novel, stable, and environmentally friendly optoelectronic material, W18O49(S) single crystal nanowires, was synthesized in this study in a furnace by using thermal chemical vapor deposition. The characterization of W18O49(S) was also shown in this work. The structure, crystallinity, and the quantity of sulfur of W18O49(S) nanowires were confirmed by X-ray diffractometer (XRD), transmission electron microscope (TEM), energy-dispersive X-ray spectrometer (EDX), and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. The results revealed that the single crystalline W18O49 nanowires were synthesized and sulfur was doped into the W18O49 successfully. The results of UV-Vis spectrum, cathodoluminescence system (CL), and photoluminescence (PL) showed that the direct band gap of W18O49(S) was near 1.7 - 1.8 eV, which could be tuned by S-doping at different S-doping concentration. The W18O49(S) nanowires exhibited high absorption coefficient up to 7.8104 cm-1 and absorption rate of 83- 95 % at = 300-1400 nm which suggest that W18O49(S) of wide spectrum absorption could serve as a light absorbing agent. The electrical property of a single W18O49(S) nanowire was measured and calculated by field-effect transistor showing a p-type, n-type and resistance property. In addition, a photo sensor and a solar cell were fabricated by W18O49(S) nanowires. The results showed a high photoconductivity gain (106-107) with good reliability and stability of photo sensor and ideal dark current curve of solar cell, which provided the feasibility of photo sensor and photovoltaic applications of the W18O49(S) nanowires presented in this study.