Research On Preparation Of ZnO Composite Film Photo-anode Of DSSC And Photoelectric Property

With rapid development, solar cell is increasingly closely related to our daily life since entered 21 st century. It also plays a more and more important role in solving the global energy and environment issues efficiently. DSSC has the advantages of simple fabrication process,low fabrication cost, high conversion efficiency and large area solar cells productivity. Hence,it become one of the heat pots in solar cells research area in recent years. Photo-anode is an indispensable part of DSSC. ZnO photo-anode has the advantages of high carrier mobility,rich raw materials, various nano-morphology preparation possibility and so on. Further more,ZnO composite film photo-anode effectively restrains dark reaction, reduces electron-hole recombination, enhances UV-Vis absorption, hence then may improve the DSSC conversion efficiency.This dissertation introduces the preparation of TiO2/ZnO composite film photo-anode of DSSC by hydrothermal method without auxiliary and studies the effects of morphology on the absorption of dyes; It introdues the design and the preparation of new type ZnO/Fe2O3 composite film DCCS and the preparation of ZnO/Fe2O3 by two steps hydrothermal methods without auxiliary;It also introduces the formation of ZnO/Fe2O3 and Fe2O3/ZnO composite film photo-anode structures with different preparation position of A1 electrode.Researches and achievements in this dissertation are as follows:1) TiO2/ZnO composite film photo-anode: The optimal preparation procedure are 0.01 M Zn(CH3COO)2·2H2O and 0.8M NaOH aqueous solution.XRD, SEM, dye absorption are developed to characterize the pyhsical characteristics and dye absoptive amount of the film.VOC, JSC, η of TiO2/ZnO composite film DSSC are superior to traditional TiO2 and ZnO:conversion efficiency(η) reaches 2.32%, open-circuit voltage(VOC) is 0.8V, short-circuit current(JSC) is 4.65mAcm-2, fill factor(FF) is 62.86%. The EIS test on TiO2/ZnO, TiO2photo-anode DSSC indicates TiO2/ZnO has bigger interface load-transferred impedance and longer electron lifetime than TiO2. It proves composite film restraints dark reaction, enhances electron transmission and transfer, hence improve DSSC conversion efficiency.2) ZnO/Fe2O3 composite film photo-anode: By studying the thickness of Fe2O3, the concentration of FeCl3 and NaNO3 and the effects of response time on composite film, andadopts XRD, SEM, UV-Vis, photo-response current to characterize to develop the optimal Fe2O3 nanorod film procedure: UV-Vis indicates ZnO/Fe2O3, Fe2O3/ZnO strength the absorptance of UV visible light. VOC, JSC, η of ZnO/Fe2O3 and Fe2O3/ZnO composite film DSSC are improved than single Fe2O3 and ZnO: ZnO/Fe2O3 conversion efficiency(η) reaches2.28%, open-circuit voltage(VOC) is 0.75 V, short-circuit current(JSC) is 4.83mAcm-2, fill factor(FF) is 61.75%. The photo-response current and DSSC conversion efficiency of ZnO/Fe2O3 composite film is also superior to Fe2O3/ZnO composite film. The reason is when ZnO contacts Fe2O3, the energy level changes, conduction band of Fe2O3 is higher than that of ZnO. Hence, it also proves that composite film improves the DSSC conversion efficiency.