Optoelectronic properties of arginine-doped tungsten disulfide quantum dots synthesized via microwave heating

摘要

Here, the hysteresis and negative photoconductivity (NPC) in arginine-doped tungsten disulfide (WS_2) quantum dots (QDs) synthesized via microwave heating method were investigated and discussed. WS_2 solution and arginine were used as the QDs and dopant sources, respectively. The structure of arginine-doped WS_2 QDs was analyzed by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The synthesized arginine-doped WS_2 QDs displays a diameter of less than 10 nm and demonstrates an excitation-dependent photoluminescence (PL) behavior. The PL intensity of arginine-doped WS_2 QDs displayed an 18 folds increase compared to the pristine WS2 QDs. The electrical transport demonstrated a p-type doping as a result of the introduction of arginine in WS_2 QDs. Ⅰ-Ⅴ measurements in varying environment and laser illumination were utilized to investigate the hysteresis and negative photoconductivity (NPC) phenomena in arginine-doped WS_2 QDs. Based on this analysis, the hysteresis and NPC are proposed to originate from the interaction of water and/or gas molecules adsorbed on the surface of arginine-doped WS_2 QDs. This optoelectronic study of WS_2 QDs is expected to contribute for the potential development and performance improvement of WS_2-QD-based devices.