Study On The Surface Plasmon Resonance Effect Of Two-dimensional WS₂ Crystal

The monolayer WS₂ crystal has a unique energy band structure is a two-dimensional semiconductor material with atomic thickness.Due to the excellent optical and electrical properties,it has a good application prospect in optoelectronic devices.However,the monolayer WS₂ crystal has a low absorption coefficient,which limits its utilization efficiency in applications.Under the irradiation of incident light,the plasma elements on the metal surface will be excited to generate a plasma oscillation mode,forming a local electric field.Through the coupling effect with the incident light,the near-field enhancement effect will occur.By constructing plasma and monolayer WS₂ structure,the photoelectric performance of WS₂ was improved.In this work,two-dimensional WS₂ crystal was grown from WS₂ powder by physical vapor deposition.Monolayer WS₂ crystal with uniform size and quality was achieved by optimizing the experimental parameters.Construction of SPR substrate,Monolayer WS₂ crystal was transferred to Si O₂/Si substrate and SPR substrate by wet transfer method.Raman spectroscopy and X-ray photoelectron spectroscopy were used to study the size,appearance and crystal quality of Monolayer WS₂ after growth and transfer.The optical properties of WS₂ were studied by photoluminescence and transient absorption spectra.The optical microscope and scanning electron microscope images showed that the appearance of monolayer WS₂ crystals after transfer did not change.Raman and XPS spectra showed that the quality of the monolayer WS₂ crystal was good.Compared with the photoluminescence of the monolayer WS₂ crystals after transfer,the photoluminescence intensity of the monolayer WS₂ crystals on the SPR substrate with the isolation layer(Si O₂)thickness of 20 nm is increased by nearly 50 times,and the relative slow decay process under the transient absorption spectrum has the longest lifetime.Further photoelectric test showed that the photoelectric performance of WS₂-SPR based photoelectric detector was better than monolayer WS₂.In this work,by constructing SPR and monolayer WS₂ structure,WS₂ thin film luminescence performance and photoelectric detector performance were significantly improved,which provided a new idea for application of two-dimensional materials.