Preparation Of WS₂ And MoS₂ Nanomaterial Absorbers Based On SiO₂ By Sol-Gel Method

WS₂ and MoS₂ have attracted wide attention of researchers as a typical two-dimensional layered material.They were widely used in new semiconductor materials,microelectronic devices,optoelectronic devices,optical instruments and other field because of their excellent electrical,mechanical,chemical,thermodynamic and optical properties.In this thesis,The WS₂ and MoS₂ saturable absorber materials based on SiO₂ were prepared by sol-gel method.XRD,SEM,Raman,TEM,XPS and other tests were carried out to analyze its morphologies and structural characteristics.And it was successfully applied to Q-switched experiments of erbium-doped fiber lasers.The main results were as follows.Firstly,SiO₂ films were prepared by sol-gel method.The effects of various factors on the surface morphology of the films were studied by controlled variable method.The experimental results show that the optimum molar ratio of the non-cracked SiO₂ film was TEOS:H2O:EtOH:HCl=1:15:10:0.1;the heat treatment rate was 0.25 ?/min below 210 ?,and 0.5 ?/min above 210 ?.The best aging time and spin coating speed were 240 h and 1500 r/min,respectively.The film prepared by the experiment is an amorphous structure film containing nano-grains.The XPS test results show that the atomic content percentages of Si and O elements in the film are 24.78%and 58.69%,respectively,and the film thickness is about 16 ?m,the transmission rate of the film is 89%.Secondly,WS₂ and MoS₂ nanoparticle solutions were prepared by liquid ph ase stripping method.The results of TEM analysis showed that WS₂ nanoparticles were?004?crystal plane preferred orientation,and MoS₂ nanoparticles were?006?and?102?crystal plane preferred orientation.Thirdly,on the basis of determining the optimal parameters of the non-cracked SiO₂ film.SiO₂ based WS₂ and MoS₂ saturable absorber films were prepared by adding WS₂ and MoS₂ nanoparticle solutions.XPS test results showed that the atomic content percentages of W and S elements in WS₂-SiO₂ film were 0.10%and 0.25%,respectively,and the atomic percentage of Mo in MoS₂-SiO₂ film was 0.23%.Fourth,the prepared MoS₂-SiO₂ film is used for the erbium-doped fiber laser.The stable Q-switched laser was obtained at 476 mW pump power with a center wavelength of 1032.5 nm and a pulse width of 3.04 ?s.