Research On The Controllable Growth Of Tungsten Disulfide And The Regulation Of Its Luminescence Performance

Tungsten disulfide,as an important member of the transition metal disulfides(TMDs),has distinguished properties,such as high switching ratio,controllable spin-orbit polarization,indirect band gap direct transition to direct band gap,strong exciton geometric constraints and tunable photoluminescence,etc..Therefore,WS2 exhibits great potential applications in solar cells,lithium batteries,light-emitting diodes and light sensors.At present,there are two main routines to obtain tungsten disulfide:one is the method from the upper to the bottom,mainly the micro-mechanical exfoliation method.The other is a bottom.up approach including chemical vapor deposition(CVD)method,hydrothermal method,vapor phase transport(VT)method and molecular beam epitaxial technology,etc..In our current study,we mainly used CVD and VT to obtain tungsten disulfide By using CVD method,single layer WS2 samples with excellent quality were obtained,but at the same time the sulfur in the reactant will produce H2S gas with the H2 reaction in the carrier gas,resulting into risks of laboratory safety.By using VT method and N2 as the carrier gas,a considerable size of single-layer WS2 cannot be obtained.With Ar/H2 as the carrier gas,through the regulation of insulation temperature,growth pressure,carrier airflow rate and other parameters to obtain a good quality of a considerable size of a single layer of WS2.We have also further done the work of using VT method to deposit WS2 on Ti3C2Tx-MXene in Ar/H2 as a carrier gas.It has also been successful obtained a single layer of WS2 with excellent quality and considerable size,and has improved the area of single-layer tungsten disulfide and the controllable degree of the experiment.The morphology of the samples was observed by optical microscopy,and the samples were characterized by fluorescence and Raman spectroscopy,atomic force microscopy and scanning electron microscopy.