Synthesis of WS1.76Te0.24 alloy through chemical vapor transport and its high-performance saturable absorption

Abstract

Layered transitional metal dichalcogenides (TMDs) are drawing significant attentions for the applications of optics and optoelectronics. To achieve optimal performances of functional devices, precisely controlled doping engineering of 2D TMDs alloys has provided a reasonable approach to tailor their physical and chemical properties. By the chemical vapor transport (CVT) method and liquid phase exfoliation technique, in this work, we synthesized WS1.76Te0.24 saturable absorber (SA) which exhibited high-performance of nonlinear optics. The nonlinear saturable absorption of the WS1.76Te0.24 SA was also measured by the open aperture Z-scan technique. Compared to that of the binary component WS2 and WTe2, WS1.76Te0.24 SA has shown 4 times deeper modulation depth, 28% lower saturable intensity and a much faster recovery time of 3.8 ps. The passively Q-switched laser based on WS1.76Te0.24 was more efficient, with pulse duration narrowed to 18%, threshold decreased to 28% and output power enlarged by 200%. The promising findings can provide a method to optimize performances of functional devices by doping engineering.

Two-Dimensional Platinum Diselenide: Synthesis, Emerging Applications, and Future Challenges

“…As a widely studied traditional crystal growth method, CVT has also been employed to direct synthesize 2D semiconductor materials, such as TiSe 2 , MoS 2 , WS 2 , and ReS 2 [137][138][139][140][141]. Benefitting from the good controllability of the growth parameters, the properties, structure, and composition of 2D materials can be well regulated.…”

“…However, the position of A 1g mode is almost unchanged for few-layer PtSe 2 and exhibits an obvious red shift as the number of layers larger than 22 layers. The layer dependence of Raman spectra properties may be attributed to the strong long-range interlayer interactions [78,79]. To further study the relationship between the thickness and Raman spectra, the intensity ratio of the A 1g peak to E g peak is extracted and plotted in Fig.…”

Optoelectronic Properties of Atomically Thin MoxW(1−x)S2 Nanoflakes Probed by Spatially-Resolved Monochromated EELS

“…when it comes to 2D TMDs, even though bulk TMD alloys have existed for decades now, a wide array of 2D TMD alloys have been synthesised in the past decade [54], thanks to the development in synthesis techniques such as chemical vapor deposition [32], physical vapor deposition [55], chalcogen exchange [32] and colloidal solution synthesis [51,52]. Even so, only a small number of alloys has been achieved so far; most of them ternary alloys based on Mo, W, S, Se and Te [16,24,32,51,52,[55][56][57][58][59][60], although new alloys with different transition metals have also been achieved [33,58,61,62], as well as quaternary alloys [17,[63][64][65][66]. Novel optoelectronic applications have arisen from these new materials [66][67][68][69].…”