铜基多层膜结构柔性透明电极的制备及应用

发布时间：2018-02-14 07:16

  本文关键词： 超薄铜薄膜 柔性透明电极 太阳能电池　出处：《山东大学》2016年博士论文　论文类型：学位论文

【摘要】：先进柔性光电以及光伏器件的迅猛发展对透明导电电极的开发提出了更苛刻的要求,高光电性能、高柔性、高稳定性同时成本低廉、制备工艺简单、易实现大规模生产的柔性透明导电电极的开发迫在眉睫。传统的单层透明导电氧化物(主要是ITO)由于价格昂贵、机械柔韧性差及不可避免的高温制备过程等不能满足相关产业的需求。目前,基于金属纳米线、纳米网格、碳纳米管以及石墨烯开发出的透明电极被认为是最有希望的ITO替代产品并得到了广泛的研究。然而上述电极仍面临各自不同的技术难题,例如：金属纳米线及纳米网格电极氧化失效问题严重,碳材料电极制备工艺不成熟光电性能远低于理论预测值。因此上述电极在短期内难以实现大面积产业化从而替代ITO。氧化物-金属-氧化物(Oxide-Metal-Oxide, OMO)多层膜结构复合电极因其简单稳定的结构、优良的机械柔性、成熟的大规模制备工艺等成为一种潜在的替代者。但受制于金属层厚度与形貌,金属基复合电极的光学性能的提高往往伴随着电学性能的损失,获得理想超薄连续金属层成为提高光电性能的唯一途径。然而由于金属与氧化物界面间润湿性较差,金属在氧化物衬底上的岛状生长模式导致很难制备超薄连续的金属薄膜。迄今为止仍未有提高Cu在氧化物衬底润湿性的相关报道。Cu基多层膜结构透明电极因其透过率较差并未得到广泛的关注。本文通过在溅射过程中引入微量02、N2来改变薄膜生长模式从而获得超薄连续的微掺杂铜(Cu(O)、Cu(N))薄膜：同时将氧掺杂铜Cu(O)薄膜用作Cu薄膜生长的润湿层制备出超薄连续的Cu薄膜。基于以上超薄连续Cu薄膜成功开发出具有优异光电性能的Cu基多层膜结构透明电极,采用上述新型Cu薄膜透明电极替代传统Cu基电极以及单层ITO电极作窗口电极的柔性有机太阳能电池的光电转换效率显著提高。主要研究内容如下：(1)通过微量的02掺杂沉积得到厚度低至2.5nm的超薄连续Cu(O)薄膜。研究证实微氧化对Cu薄膜生长初期纳米团簇在ZnO衬底上迁移运动的抑制是导致更早形成超薄连续薄膜的原因。采用Cu(O)作为中间金属层的ZnO/Cu(O=5.0%)/ZnO电极光电性能优异(可见光区平均透过率达到83%,面电阻低至13Ωsq-1)及抗氧化性。采用Cu(O)基多层膜结构电极为窗口电极的有机太阳能电池转化率高达7.5%,高于采用传统Cu薄膜电极和ITO电极的电池效率。(2)为了避免Cu靶材在02环境中因氧化导致的靶中毒问题以及大面积样品制备过程中氧浓度不易控制等技术难题,采用相对惰性的N2代替O2研究了氮掺杂对Cu薄膜生长模式的影响。研究发现低于1at.%的氮掺杂足以引起Cu薄膜形貌发生显著变化。N原子在Cu纳米团簇表面的吸附削弱了Cu原子间的内聚能,抑制其三维岛状生长,较早地形成连续的氮掺杂铜Cu(N)薄膜。基于此结果开发出一种价格低廉、制备工艺简单可行,同时光电性能优于传统采用Cu薄膜作为中间金属层的多层膜结构电极的ZnO/Cu(N)/ZnO电极。采用该电极制备得到光电转换效率为7.1%的柔性有机太阳能电池。(3)利用1nm-Cu(O)薄膜作为Cu薄膜沉积的润湿层,制备得到完全连续的Cu(O)/Cu复合薄膜,发现Cu在Cu(O)表面以一种类外延的二维层状模式生长。由于降低了中间金属层中的杂质浓度,基于此开发出的ZnO/Cu(O)/Cu/ZnO电极光电性能得到进一步提高,表现出优于ITO电极的光电性能,其可见光区平均透过率高于85%,面电阻低至11Ωsq-1。采用该电极为窗口电极的柔性有机太阳能电池光电转化效率高达7.72%。综上,本文提供了一种在氧化物衬底上制备超薄连续金属薄膜的有效方法,并对金属润湿性改善的深层机理进行了初步探讨。基于改进后的超薄连续Cu膜制备得到光电性能优异的Cu基多层膜结构电极,解决了柔性衬底上制备高品质透明导电薄膜的技术难题,同时采用该电极制备得到高光电转化效率的有机光伏器件。
[Abstract]:More stringent requirements for the development of the advanced photoelectric flexible transparent conductive electrode and the rapid development of photovoltaic devices, high optical performance, high flexibility, high stability and low cost, simple preparation process, easy to realize the development of mass production of flexible transparent conductive electrode is imminent. The traditional single layer transparent conductive oxide (ITO) because the price is high, not high temperature preparation process such as poor mechanical flexibility and the inevitable to meet the needs of industry. At present, the metal nanowires based on nano grid, carbon nanotubes and graphene transparent electrode developed is considered the most promising ITO alternative products and has been extensively studied. However, the electrode still faces different technical problems, such as: metal nanowires and nano grid electrode oxidation failure problems of carbon electrode preparation technology not mature photoelectric The performance is far lower than the predicted values. So the electrode in the short term is difficult to achieve a large area of industrialization as an alternative to the ITO. oxide metal oxides (Oxide-Metal-Oxide, OMO) multilayer structure composite electrode due to its simple structure and stability, excellent mechanical flexibility, mature large-scale preparation process as a potential replacement. But subject to the metal layer thickness and morphology, optical properties of metal matrix composite electrode to improve the electrical properties often accompanied by loss, obtain the ideal thin continuous metal layer has become the only way to improve the photoelectric performance. However due to the metal and oxide interface between poor wettability of metal oxide in the substrate leads to island growth mode to prepare ultrathin continuous metal films. So far there is no relevant reports in Cu to improve the wettability of.Cu based oxide substrate layer structure because of its transparent electrode The poor rate has not been widely concerned. Through the introduction of trace in the sputtering process 02, N2 to change the film growth model to obtain ultrathin continuous micro copper doped (Cu (O), Cu (N)) and oxygen doped copper film: Cu (O) thin film was used as a wetting layer of Cu thin film growth system preparation of ultra-thin continuous Cu films. Above ultrathin continuous Cu films successfully developed a Cu based multi layer structure of transparent electrode has excellent photoelectric properties based on the photoelectric conversion efficiency of the new Cu thin film transparent electrode to replace the traditional Cu based electrode and ITO electrode as the single window electrode of flexible organic solar cells increased significantly. The main research the contents are as follows: (1) get thin continuous Cu thicknesses as low as 02 2.5nm through doping deposition trace (O) films. Studies have confirmed that micro oxidation initial growth of nanoclusters on ZnO substrate inhibited migration movement is on Cu thin film The cause of formation of thin continuous film. Earlier by Cu (O) as an intermediate metal layer ZnO/Cu (O=5.0%) /ZnO electrode with excellent photoelectric performance (average visible transmittance reaches 83%, the surface resistance as low as 13 SQ-1) and antioxidant activity. Using Cu (O) based layer structure electrode for organic solar cell window the electrode conversion rate as high as 7.5%, higher than that of the conventional Cu electrode and ITO electrode film battery efficiency. (2) in order to avoid the problems caused by the target poisoning Cu target in the 02 oxidation environment and a large area in the sample preparation process of oxygen concentration is not easy to control and other technical problems, using relatively inert N2 instead of O2 research the effect of nitrogen doping on the growth mode of Cu thin film. The study found that lower nitrogen doped 1at.% cause Cu thin film morphology change of.N atom in Cu nanoclusters adsorption weakens the Cu interatomic cohesive energy, suppression of the 3D Island growth, early formation of nitrogen doped copper continuous Cu (N) thin film. The results to develop a low price based on the preparation process is simple and feasible, and better than the traditional photoelectric properties of Cu thin films as electrode structure with intermediate metal layers of multilayer films of ZnO/Cu (N) /ZnO electrode using the electrode preparation. Get the photoelectric conversion efficiency of flexible organic solar cell 7.1%. (3) using 1nm-Cu (O) film as a wetting layer deposited Cu films, prepared by continuous Cu (O) /Cu composite films were found in the Cu Cu (O) surface growth in two dimensional layered model a kind of extension. Due to the reduction of the concentration of impurities in the intermediate metal layer, the development of ZnO/Cu (O) based on the photoelectric properties of /Cu/ZnO electrode has been further improved, showing the photoelectric performance is better than that of ITO electrode, the average visible transmittance is higher than 85%, as the window of the electrode by surface resistance as low as 11 sq-1. Flexible organic solar cell photoelectric conversion efficiency and electrode up to 7.72%. in summary, this paper provides an effective method for preparation of ultra-thin continuous metal films in the oxide substrate, and the underlying mechanism of metal wettability improvement were discussed. Ultra thin continuous Cu membrane modified by Cu based multi layer structure the electrode based on excellent optoelectronic properties, to solve the technical problems of high quality transparent conductive film prepared on flexible substrate, and the electrode prepared by high photoelectric conversion efficiency of organic photovoltaic devices.

【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TB383.2;TM914.4
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本文编号：1510161