Research On The Properties Of Infrared Absorption Based On Graphene/Black Silicon

Black silicon(B-Si)has significant potential for applications in the fields of photovoltaic and optoelectronic detection due to its excellent anti-reflection properties and light absorption characteristics.The main limitation on the light absorption characteristics of black silicon is the bandgap width of the silicon material(E_g=1.12e V),which results in the absorption of black silicon to rapidly decrease above the 1100nm wavelength range.Graphene,with its two-dimensional structure and unique optoelectronic properties,has received considerable attention as one of the many technological options for broadening the infrared absorption spectrum of black silicon.To further promote the application of black silicon,research into the technology of fabricating infrared structures by attaching graphene layers onto textured black silicon surfaces has become one of the research hotspots in this field.This thesis aims to study the optical properties of black silicon microstructures and graphene.Through a research plan that includes simulation and experiments,multiple model feature parameters were simulated and analyzed for their optical properties.In the process of the study,the morphological characteristics and optical properties of micro-pyramid-nanoporous black silicon were optimized at different stages of preparation,significantly enhancing the light absorption performance within the black silicon’s bandgap width.Additionally,a graphene/black silicon(G/B-Si)infrared absorption structure was prepared by introducing graphene material onto the surface of black silicon.The use of graphene’s indiscriminate absorption in the near-mid infrared range improved the infrared absorption capacity of the structure.The main work of the study includes:1.The established Rough Surface Rectangular Pyramid(RSRP)black silicon model accurately predicted the trend of the effect of micro-pyramid-nanopore black silicon surface microstructure on optical properties,and the light absorption of the structure can be significantly improved by adding surface roughness structures with amplitudes around100nm.2.The established graphene sheet model can accurately simulate the change in the light absorption of graphene sheets stacked on the substrate surface,and oxygen-containing functional group doping of graphene significantly affects its infrared absorption performance.3.Micro-pyramid-nanopore black silicon was obtained through alkali etching and metal-assisted etching technology,with an average surface reflectance of 3.71%in the380-1100nm range and an average absorption rate of up to 93.70%.In addition,the effects of different experimental conditions on the formation of surface microstructures in the preparation technology were determined.4.Comparing G/B-Si infrared absorbing structures obtained by electrophoretic deposition and dip-coating methods,the electrophoretic deposition of graphene layer can significantly improve the absorption of the structure in the infrared band,with an average absorption rate of 91.01%in the 380-1400nm range.The dip-coating method can obtain a continuous and smooth large-area graphene layer on the black silicon textured surface,showing further enormous potential for composite with other structures.