Preparation And Characterization Of Film Materials For CuInS₂/ZnS Solar Cell

Solar battery has gradually become the main device which is used to solve the energyproblems, CIS solar battery has higher photoelectric conversion efficiency and stableperformance. So it is the most potential solar cells.There are lots of methods which are usedto prepare CIS series solar materials. However, the traditional methods such as Depositionsputtering needs high cost, difficult conditions which are hard to control, what’s worse that itis difficult to control the crystal morphology. And the light absorption properties of thecrystals which are prepared by the traditional methods are very low.In order to solve theseproblems, this paper prepared the CIS solar cell materials by different solution and analyzedits absorption properties. The main research contents are mainly the following three aspects.First of all, this thesise synthesized CuInS₂flake crystals by hydrothermal route using（NH₂）₂CS, CuCl₂2H₂O and InCl₃4H₂O. And respectively discussed the influences oftemperature, time, pressure conditions on the structure, shape and light absorption of CuInS₂flake crystals.In addition that, this paper also synthesized ZnS crystal ball by hydrothermal routeusing （NH₂）₂CS, Zn（CH3CCO）2·2H₂O and respectively discussed the influences oftemperature, time, pressure conditions on the structure, shape and light absorption of ZnSCrystal ball. Then make a simple exploration to the synthesized mechanism.Finally we made CuInS₂and ZnS coating using PVDF by coating method. Thenanalysized light absorption performance of the coating.Crystal structure and performance of CuInS₂and ZnS were characterized by scanningelectron microscope （SEM）, nergy spectrum analysis （EDS）, Fourier infrared spectrometry（FT-IR）,X-ray diffraction （XRD） and so on.The results show that:1)Temperature has great effects on phase structure of CuInS₂, crystal purity increasesgradually with the rise of temperature. Pure CuInS₂crystals were gotten when thetemperature were above150℃, Otherwise crystals contained CuS impurities.Time affectedgreatly crystal morphology, the longer the reaction last,the more perfect crystal grew. Flakesof cuInS2crystals were more perfect when it react15h. Pressure affected the structure ofCuInS₂greatly.The CuInS₂which was synthesized under atmospheric condition containedCuS impurities. The pretreatment of the reactants played an import role in the Surfacemorphology of CuInS₂. Flake CuInS₂crystals which were Scattered evenly could beobtained when reactants were dissolved by high temperature. Pure sheets of CuInS₂crystalsof which the average particle size is between160nm and170nm were gotten by reacting15 h at190℃whenreactants were dissolved by high temperature.The CuInS₂has a stronglight absorption efficiency between visible region and part of uv region.The crystal’sforbidden band width is about1.43ev.2) Temperature, time has greater influences on the structure and surface morphology ofZnS.Pure and scattered evenly ZnS crystal balls were prepared under150℃and reating12h.Surfactant CTAB could solve the reunion of ZnS crystals When the concentration of CTABis1mmol/L.The distribution of particle size were scattered evenly. The light absorption ofZnS crystal balls were higher between200nm-350nm than others. The crystal’s forbiddenband width is about3.3ev.3) ZnS, CuInS₂could be better dispersed in PVDF which had little effect on lightabsorption performance of ZnS, CuInS₂coating. CuInS₂/PVDF film absorbing layermaterials’ forbidden band width is about1.42ev, and ZnS/PVDF film window layermaterials’ forbidden band width is about3.3ev. Both of these layer materials are optimalmaterials which are used for CIS Solar cells.