【作者】 杨波；

【导师】 李广；

【作者基本信息】 安徽大学 ， 材料科学与工程， 2016， 硕士

【摘要】 太阳能电池作为一种永续的新型能源,具有无污染、储量大、能够直接利用等优点。在能源利用方面具有特殊的优势,尤其是将其应用于建筑物的屋顶,建造大规模的屋顶发电站,可以减少目前电力系统远距离输送所产生的能源损耗。然而,太阳能电池经过几十年的发展,由于生产成本高、转化效率不高等因素仍然没有大规模的应用。因此,寻找低成本、高转化效率的太阳能电池材料具有高度的实际意义,是世界各国科学家的研究重点。染料敏化太阳能电池以其较高的转化效率、简易的组装技术、低能耗和零污染等优点引起了广泛的关注。金属硫属化合物纳米材料以其独特的成键特点和特殊结构,在电学、光学、磁学等学科表现出优异的性能,成为近年来纳米材料科学领域的热点。其中,SnS,SnS2等锡硫化合物是重要的中间带半导体材料,也是重要的纳米催化剂材料。相关研究表明纳米结构的锡硫化合物材料有望在锂离子电池、光电子元器件、催化剂、光伏发电等领域有着广泛的应用。同时,金属硫化物与石墨烯(RGO)的复合被认为是提高材料催化及电学性能的重要手段。对于SnSx纳米材料及其与RGO的复合材料的研究目前已取得了很大的进展,但在一些方面(比如石墨烯的团聚问题、催化剂的催化效果、复合材料微观形貌的控制等)仍然存在着很多挑战。基于此,本文以SnSx纳米材料及其与RGO的复合材料为研究对象,并探究了其作为染料敏化太阳能对电极材料的性能。本论文分为五章。第一章首先分析了SnSx的结构特点,电学、光学性质,及其在新能源领域的应用。然后介绍了光伏材料方面的最新研究进展,尤其是染料敏化太阳能对电极材料的最新进展。第二章主要介绍了通过溶剂热法合成了具有(001)晶面取向生长的SnS2纳米材料。通过调节混合溶剂的比例,SnS2的(001)晶面表现出一定的择优取向,I-V特性及电化学性能测试表明沿(001)晶面取向生长的SnS2,相应的电池表现出较高的光电转换效率和较好的电化学性能。第三章主要研究了SnS2和RGO复合材料的溶剂热合成并探究其I-V特性及电化学性能。结果表明,在SnS2与RGO协同作用下,复合材料的性能相对于单独的SnS2或RGO都有显著的提高。第四章主要探究了溶剂热法合成的SnS2与RGO原料进行简易物理混合后用作染料敏化太阳能对电极材料时性能。初步探索了SnS2与RGO的物理协同机制。研究发现,在混合6%质量分数的RGO时,SnS2/RGO电极表现出较高的光电转换效率和较好的电化学性能。第五章主要探索了对电极制备的后续退火过程对材料相变的影响。利用后续退火将结晶度差的SnS2转变为结晶度较好的SnS纳米材料,同时研究了其与RGO的复合过程。I-V特性及电化学性能测试表明,与结晶度较差的SnS2及其与RGO复合材料相比,经退火相变之后的SnS及其与RGO复合材料均表现出更高的效率和更好的性能。更多还原

【Abstract】 As a re-new-energy, solar cells have many advantages, such as non-pollution, large reserves, ease of use. There are some special advantages, especially in the roof power plant. They can greatly decrease the network losses. However, the large-scale of solar cells is not applied due to the high cost of production, low conversion efficiency, etc. Therefore, the finding of low-cost, high-conversion efficiency materials possess high real meaning. The dye-sensitized solar cells (DSSCs) are given occasion to tremendous interest and large-scale research in numerous academic laboratories.Due to the unique bonding characteristic and special construction, metal chalcogenides nanomaterials possess many excellent proprieties on electricity, photology, magnetism, etc. This given occasion to tremendous interest and large-scale research in numerous academic laboratories. SnS and SnS2 are crucial mid-band gap semiconductors and nanometer catalysts. Besides, SnSx nanomaterials are considered to have potential application in lithium battery, optical-electronics component, catalyzer, photovoltaic, etc. However, bare SnSx cannot achieve excellent performance in a catalytic reaction. To solve this disadvantage, a composite of SnSx with RGO may be a great choice. As for SnSx and a composite of SnSx with RGO, although the efforts about these respects have been made great advance, there are still many problems to be solved, such as the reunion of grapheme, the effect of catalyst, the microstructure of the composite. Therefore, this thesis aims to investigate the catalytic activities through I-V curves and conversion efficiency tests as the CE in DSSCs based on SnSx nanomaterials and SnSx with RGO nanocomposites.This thesis contains five chapters. The first chapter mainly presents the structures, electricity propriety, photology, and the application in the new energy field. Then we review the latest processes in the photovoltaic, especially for the counter electrodes of dye-sensitized solar cells.In the second chapter, we focused on synthesizing hexagonal SnS2 nanoparticles with perfect crystallinity along the (001) facet by changing the proportion of mixed solvent. We found that hexagonal SnS2 nanoparticles with perfect crystallinity along the (001) facet were prospective material for enhancing the photovoltaic performance of CEs in DSSCs.In the third chapter, a nanocomposite of SnS2 nanoparticles with RGO were synthesized. The effectiveness of this nanocomposite exhibited remarkable electrocatalytic properties upon reducing the triiodide, owning to synergistic effects of SnS2 nanoparticles dispersed on graphene sheet and improved conductivity.In the fourth chapter, the nanosheet-assembled SnS2 microspheres were synthesized through a solvothermal method, and the catalytic activities of the microspheres were investigated by Ⅰ-Ⅴ and electrochemical performance tests as counter electrodes in dye-sensitized solar cells. To further improve the power conversion efficiency of the counter electrode of the microspheres, different amounts of reduced graphene were added into the microspheres by simply physical mixing. With the addition of 6 wt% reduced graphene, the cell performed a higher power conversion efficiency.In the last chapter, we report such a phase transition in which tin (Ⅳ) sulfide is transformed into tin (Ⅱ) sulfide after annealing in an argon atmosphere. The precursor and final product are respectively fabricated together with reduced graphene to form nanocomposites that are subsequently used as the counter-electrodes. It is found that the power conversion efficiency of dye-sensitized solar cell with the counter-electrode made of tin (Ⅱ) sulfide and reduced graphene oxide nanocomposites achieves higher power conversion efficiency than that of a device using tin (Ⅳ) sulfide and reduced graphene oxide nanocomposites as counter electrode.更多还原