液相法制备铜锌锡硫纳米颗粒及其光电性能研究

发布时间：2018-03-22 04:23

本文选题：液相法　切入点：Cu2ZnSnS4(CZTS)　出处：《河南大学》2014年硕士论文　论文类型：学位论文

【摘要】：硫族半导体是一种重要的半导体材料。近年来科研工作者对硫族半导体纳米晶的合成、物理性质和其在很多方面的应用都进行了深入的研究。而铜锌锡硫（Cu2ZnSnS4，CZTS）作为一种四元硫族化合物半导体，可以看作是锌和锡以1:1的比例取代CuInS2中的In而得到的。 CZTS材料的合成方法大致可分为：真空法和液相法。真空法主要是通过溅射或蒸发的方法来制备CZTS薄膜。这些方法大多需要较苛刻的实验条件：如高温高压。这就导致该方法对设备的要求较高，能耗也较高。为了降低成本，液相法得到了发展。因为纳米晶墨水可以通过旋涂、滴涂、喷墨打印等方法直接成膜，不需要依赖大型的真空设备，从而降低了成本，有利于大规模生产。所以不同形貌和结晶度的CZTS纳米晶陆续被合成出来。在本论文中我们用简单的液相法合成了纤维锌矿CZTS纳米梭和球状锌黄锡矿CZTS纳米颗粒。纳米梭的长度为100-150nm，宽度为30-40nm，并研究了纳米梭的光电性质，并将其铺成薄膜尝试应用于薄膜太阳电池中。球状CZTS纳米颗粒的尺寸为300-500nm，，并将其应用作锂离子电池其负极材料。本论文的工作主要包括以下几个部分: （1）我们用简单的一锅法在不需惰性气体保护的条件下合成了亚稳态的纤维锌矿CZTS纳米梭。用XRD，TEM和SEM对合成的CZTS纳米梭的结构和形貌进行了表征。通过UV-vis吸收和反射光谱对纳米梭的光学特性进行了表征，发现与CZTS纳米晶相比CZTS纳米梭在可见光区有较强的吸收。这可能是由于纳米梭薄膜具有较强的光陷阱效应，导致其对光的吸收更有效。我们还对CZTS的光电性质进行了探究。通过I-V测试和Hall效应测试，我们发现与CZTS纳米晶相比CZTS纳米梭的载流子浓度较高，电阻率较小。这些结果表明，CZTS纳米梭有利于增加载流子浓度和提高电子传输。 (2)将CZTS纳米梭配制成纳米墨水，并用滴涂法铺膜。将CZTS纳米梭薄膜硒化得到CZTSe薄膜，并将其组装成CZTSe薄膜太阳电池，并对电池的性能进行了I-V测试。由于无法精确控制组装过程中的工艺条件，致使电池的性能结果并不理想。所以想要制造低价高性能的光伏器件还有很长的路要走。 (3)我们用溶剂热法合成了球状300-500nm的Cu2ZnSnS4(CZTS)纳米颗粒。从SEM和TEM图中我们发现较大的球状CZTS纳米颗粒是由更小的CZTS纳米晶堆积而成的。CZTS纳米颗粒作为锂离子电池的负极材料时，在经过多次循环后仍能够保持较稳定的Li+的插入/脱出过程。其电化学性能可以归因于纳米颗粒的分级纳米结构和铜/锌诱导产生的有效的电荷传输。这些性质表明CZTS纳米材料在锂离子电池负极材料中的潜在应用价值。
[Abstract]:Sulfur semiconductor is an important semiconductor material. The physical properties and their applications in many fields have been studied in depth. As a quaternary sulfur compound, copper, zinc, tin sulfide Cu2ZnSnS4CZTSS can be regarded as the substitution of zinc and tin for in in in CuInS2 at 1:1. The synthesis methods of CZTS materials can be roughly divided into vacuum method and liquid phase method. The vacuum method is mainly by sputtering or evaporation to prepare CZTS thin films. Most of these methods require harsh experimental conditions, such as high temperature and high pressure. This leads to a higher demand for equipment, In order to reduce the cost, the liquid phase method has been developed, because nanocrystalline ink can be directly coated by spin-coating, droplet coating, inkjet printing and so on, without the need to rely on large vacuum equipment, thus reducing the cost. Therefore, CZTS nanocrystals with different morphology and crystallinity were synthesized one after another. In this paper, we have synthesized CZTS nanoparticles of wurtzite CZTS and CZTS nanoparticles of spherical zinc-yellow tin ore by simple liquid phase method. The length and width of the shuttle are 100-150 nm and 30-40 nm, and the photoelectric properties of the shuttle are studied. The spherical CZTS nanocrystalline is 300-500nm in size and is used as the anode material of lithium ion battery. The work of this thesis mainly includes the following parts:. (1) the metastable wurtzite CZTS nanoshuttles were synthesized by a simple one-pot method without inert gas protection. The structure and morphology of the synthesized CZTS nanoshuttles were characterized by XRD-TEM and SEM. The structure and morphology of the synthesized CZTS nanoshuttles were characterized by UV-vis absorption and inversion. The optical properties of the nano-shuttle were characterized by emission spectra. It is found that compared with CZTS nanocrystals, CZTS nanoparticles have strong absorption in the visible region, which may be due to the strong light trap effect of the nano-shuttle films. We also investigated the optoelectronic properties of CZTS. By I-V test and Hall effect test, we found that the carrier concentration of CZTS nanoparticles was higher than that of CZTS nanocrystals. These results indicate that the CZTS nanoparticles can increase the carrier concentration and increase the electron transport. (2) the CZTS nano-shuttle was prepared into nano-ink and coated with dripping method. The CZTSe film was prepared by selenization of the CZTS nano-shuttle film and assembled into a CZTSe thin film solar cell. The performance of the battery is tested by I-V. The performance of the battery is not satisfactory because the process conditions in the assembly process can not be controlled accurately, so there is still a long way to go to make the photovoltaic device with low cost and high performance. (3) the spherical 300-500nm nanocrystalline Cu2ZnSnSS4CZTS was synthesized by solvothermal method. From the SEM and TEM diagrams, we found that the larger spherical CZTS nanoparticles were formed from smaller CZTS nanocrystals, which were used as negative electrode materials for lithium-ion batteries. The electrochemical properties of Li can be attributed to the graded nanostructures of nanoparticles and the effective charge transport induced by copper / zinc. The potential application value of CZTS nanomaterials in cathode materials of lithium ion batteries is indicated.
【学位授予单位】：河南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：O611.4;TM912

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