| In the21st century, the most concern is the problems of energy andenvironment, as global energy consumption and increasing pollution of theenvironment, people are strongly looking for new materials to reduce theenvironment pollution, and therefore solar cells received people’s high attention,CuInSe2(CIS) solar cell are widely recognized by its irreplaceable advantages.ZnS thin film is used for buffer layer in CIS cells due to its good stability,non-toxic and harmless and fast blue response compared with CdS; ZnO thin filmhas large band gap, easy to doping, the transmittance is high in visible light, andtherefore used for window layer in CIS solar cell. There are many ways toprepare the two films, the electrodeposition method has a simple process, whichhas high productivity and low cost, suitable for large area deposition, and drawshigher attention.In this paper, we prepared ZnO and ZnS thin films by electrodeposition.Firstly, the substrate of the conductive glass (FTO) is taken pretreatment, then weprepare the electrolyte, choosing the mixed solution of Zn(NO3) and NaNO3asthe electrolyte of ZnO; Choosing the mixed solution of ZnSO4, Na2S2O3andC6H5Na3O7·2H2O as the electrolyte of ZnS. On the basis, the two films isdeposited, technological conditions for preparation of ZnO films are optimized byorthogonal experiment, technological conditions for preparation of ZnS filmswere optimized by single-factor experiment, Finally, we get the optimumtechnological conditions of the two films.In the experiment, the reaction mechanism of ZnO thin films is explored byusing LSV; XRD is used to qualitative analyze phase structure of ZnO and ZnSthin films; Thermo-Needles experiment is used to analyze electric conductiontype of the ZnO and ZnS thin films; SEM and AFM is used to analyze the surfacemorphology of ZnO and ZnS films; EDS and XPS is used to analyze the component and element content; UV-vis is used to analyze the opticaltransmittance of two films. The results show that the deposition rate of ZnO thinfilm get faster as the increase concentration of Zn2+; ZnO and ZnS films are bothwurtzite structure; ZnO and ZnS films belong to n-type semiconductor. Thesurface of ZnO films is compact, uniform distribution, the porosity is small, andwith less impurity content. The surface of ZnS films is compact, and wellcombined with the substrate; The transmittance of ZnO films is more than80%inthe visible range, and one of the ZnS films reaches40%, the bandgap of ZnSfilms is3.68eV. |
