ZnO纳米线阵列的制备及其在DSSC电池中的应用

【作者】 夏文高；

【导师】 邓宏；

【作者基本信息】 电子科技大学 ， 材料科学与工程， 2010， 硕士

【摘要】 染料敏化太阳能电池(DSSC)作为一种新型光电化学太阳能电池,以其制作工艺简单、成本低、理论上很大的电池总效率提升空间,且对环境良性,而具有很好的应用前景。目前,以TiO2薄膜作光阳极的DSSC电池的光电转化效率最高可达11%。但是纳米晶多孔TiO2薄膜中大量表面态的存在,使DSSC电池转换效率降低。ZnO作为有望取代TiO2的氧化物之一,近年来,以阵列ZnO纳米线、棒、片作光阳极的DSSC电池研究取得了较大的发展。在这些电池中引入的直线电子传输理论认为:电子在垂直于导电基底的单晶阵列结构中传输具有极高的传输速率和最低损耗。在相同条件下,与TiO2纳米粒子相比较,用ZnO纳米线阵列制备的光阳极具有更好的光电转换效率。单晶半导体纳米线阵列的引入,可以有效地降低电子传输的晶界势垒和传输损耗,提高电荷传输能力,从而提高光电转换的效率,它已成为染料敏化电池光阳极新的研究方向。本文探讨了应用于DSSC电池的ZnO纳米线制备工艺,在优化工艺条件下制备得到呈现阵列排列特性的ZnO纳米线,并以此作为染料敏化太阳能电池光阳极材料。主要研究内容为:(1)采用低温化学气相沉积法(CVD)制备ZnO纳米线阵列,讨论了衬底、催化层、温度条件和载气氩气的气氛条件对ZnO纳米线阵列的影响。材料微结构表征和分析表明,制备ZnO纳米线阵列的优化工艺条件为:在AZO膜上,以铬作为催化剂,ZnO源最高分解温度为1350℃,衬底温度最高在450℃-500℃之间,氩气在源温到达最高时通入,流量保持35sccm不变,通气40min后,开始降低源分解温度至1100℃,整个氩气通气时间为1小时,也就是纳米线的生长时间为1小时;(2)将优化工艺条件下制备得到的ZnO纳米线阵列应用于DSSC电池,得到电池开路电压350mV,短路电流0.68mA/cm2,填充因子为32.8%,总效率为0.078%。更多还原

【Abstract】 Dye-sensitized nanocrystalline solar cell is a new type of photoelectric chemical solar cell, which has become an arresting point of academy in the world due to its qualities such as simpleness of preparation, low cost, large potential for improvement considering the theoretical photoelectric conversion efficiency and friendly environment action. At present, the photoconversion efficiency of DSSCs with TiO2 thin film photoanodes had the best performance of 11%, but it is precisely because the existence of a large number of surface states in porous nanocrystalline TiO2 thin films, the conversion efficiency of DSSCs decline. ZnO as the one to replace TiO2, in recent years, the research in ZnO nanowires, rods and films have made great development. In these cells the introduction of linear electron transfer theory thought of that E-perpendicular has a very high transmission rate and the minimum loss in the conductive substrate with crystal arrays structure. Under the same conditions, the photoconversion efficiency of DSSCs with well-aligned ZnO nanowire arrays photoanodes performance better compared with the TiO2 nanoparticles. Therefore, in electronic transmission the introduction of single-crystal structure semiconductor with nanowire arrays can effectively reduce the grain boundary barrier and the transmission loss, so to improve the capacity of charge transmission and enhance the photoconversion efficiency, for that it has become a new research direction in dye-sensitized cell photoanodes.In this paper, the preparation craft of ZnO nanowires which were applied for DSSCs was investigated, well-aligned ZnO nanowire arrays were synthesized under optimize craft, and then it was introduced to apply for the DSSCs’s photoanodes,the primary results are shown as follow:(1)The ZnO nanowire arrays were synthesized via chemical vapor deposition (CVD) method,the preparation craft parameters such as substrate, catalyst, temperature and the Argon gas were found to greatly affect the ZnO nanowire arrays. The results by materials microstructure show that it is the optimize craft of the ZnO nanowire arrays: Al-doped ZnO transparent conductive films (AZO) was selected to use for the substrate, Chromium was chosen for catalyst, when the highest reaction temperature of source came to 1350℃, the highest substrate temperature maintained about 450℃-500℃, and the Argon gas flow rate was 35 sccm,40 minutes later,the reaction temperature of source began to drop to 1100℃,in the process, the growth time of ZnO nanowires maintained for 1 hour.(2)Based on this DSSCs with the ZnO nanowire arrays Photoanodes which were synthesized under optimize craft, the open circuit voltage of 350mV, short circuit 0.68mA/cm2, fill factor of 38.2% and the total efficiency of 0.078% were obtained.更多还原