Preparation Of Silver-based Ternary Sulfide And Calculation Of Energy Band

Solar energy is widely used now due to its advantages of pollution-free and easy-to-obtain.Especially in recent years,the rapid development of solar cells has gradually attracted people's attention.The research on existing solar energy tends to be perfect.Therefore,the research on new and efficient solar cells is the innovation of current solar cells.The structural similarity between silver-based chalcogenide ternary compound and copper-based ternary compound,as well as its higher band gap width and better optical properties determine that it can be applied to the field of solar cell absorption layer.In this paper,the CASTEP program built in MS is used to calculate the band and optical properties of Ag-??In,Ga,Al?-??S,Se,Te?₂ and AgIn_0.5Ga_0.5S?Se,Te?₂,AgGa_0.5Al_0.5S?Se,Te?₂ under PBE advantages.AgInS₂ and AgInSe₂ films were prepared by spin-coating co-reduction method,and the products,morphology and properties of the samples were characterized by X-ray diffractometer,scanning electron microscope?SEM?and energy dispersive spectrometer?EDS?.?1?Using CASTEP program built in MS,based on geometric structure optimization,exchange correlation can be calculated by PBE pseudopotential of generalized gradient approximation?GGA?under density functional theory.Calculation of the band gap and optical properties of Ag-??In,Ga,Al?-??S,Se,Te?₂ and AgIn_0.5Ga_0.5S?Se,Te?₂,AgGa_0.5Al_0.5S?Se,Te?₂ with yellow ore structure shows that the band gap of Ga and AI doped crystals is always between undoped Ag-??In,Ga,AI?-??S,Se,Te?₂ crystals,and the absorption coefficient of Ga and Al doped crystals is the highest at the wavelength of about 200nm?the critical points of far violet wave length and near violet wave length?,followed by the absorption coefficient at the wavelength of 380nm-780nm?visible light?,and the lowest at the wavelength of 780nm or more?infrared light?.The reflectivity reaches the maximum at the wavelength of about100nm-140nm?far ultraviolet light?,and the reflectivity of each crystal finally tends to a certain stable value with the increase of wavelength.?2?AgInS₂ thin films were prepared by spin-coating co-reduction method.When the solvent is anhydrous ethanol,the reaction product is mainly orthorhombic AgInS₂.The crystallization effect is best when the reaction temperature is 220?,the reaction time is 20h,and the number of spin-coating times is 4.In terms of appearance,agglomeration and caking are common,and the film coating is uneven.Crystalline crystals are mostly spherical,and spherical crystals have slight agglomeration phenomenon.The length of small agglomerated crystals is about 0.1?m-0.15?m,and the length of single spherical crystals is mostly 0.05?m-0.1?m.Agglomeration tends to worsen with the increase of reaction time and reaction temperature.AgInS₂ films were also successfully prepared using deionized water as solvent.However,the phenomenon of agglomeration and caking is common in terms of morphology,and the film coating is uneven.?3?AgInSe₂ thin films were prepared by spin-coating co-reduction method.When the solvent is deionized water solution,the reaction products are mainly tetragonal AgInSe₂ and orthorhombic AgInSe₂.The crystallinity effect is best when the reaction temperature is 180?and the reaction time is 30h and the number of spin-coating times ia 4.In terms of appearance,the film is mainly composed of large block,small block and strip crystals.The film is uneven in overall ravine,agglomeration and coating.The crystal consists of massive,massive spherical and a few massive crystals.The length of massive crystals is about 0.3?m-1.5?m,the length of massive spherical crystals is mostly 0.05?m-0.1?m,and the length of massive crystals is about 0.5?m.When deionized water is used as the solvent,the crystallization effect is far less than when the solvent is anhydrous ethanol.Crystals with different morphologies were prepared,but agglomeration and caking were common,and the coating was uneven.