基于金属纳米粒子局域表面等离子体增强型聚合物太阳能电池的研究

发布时间：2018-01-04 16:18

本文关键词：基于金属纳米粒子局域表面等离子体增强型聚合物太阳能电池的研究　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：聚合物太阳能电池由于具有重量轻、成本低、柔性等独特的特点而与传统的无机薄膜太阳能电池形成了激烈的竞争。在过去几年中,科研人员对聚合物太阳能电池的研究已经深入到了各个方面,其中包括电子给体和受体材料的合成,界面修饰,纳米颗粒的掺杂,光捕获方法,串联结构等,这使得聚合物太阳能电池的能量转换效率已经超过了10%。然而,与无机太阳能电池相比,聚合物太阳能电池相对较低的能量转换效率则限制了其进一步的发展与应用。从聚合物太阳能电池的基本工作原理来看,其外部量子效率由内部量子效率和吸收效率的乘积来确定的。尽管许多聚合物材料具有较高的吸收系数(105cm-1),但与具有相对较大的带隙的硅材料相比,聚合物材料仍然难以吸收足够的光以用于太阳能电池中。因此,为了达到既增强器件的光吸收又不增加聚合物太阳能电池活性层厚度的目的,产生了一种光捕获方法(或光管理)。目前,各种光捕获方法都已经得到了广泛的应用,其中包括微腔结构,光子晶体和等离子体纳米结构。在这些方法中,值得特别关注的是基于光学性质的等离子体激元纳米结构,由于其独特的可调光学共振特征而吸引了很多关注。实验中,将通过等离子体共振效应来达到提高聚合物太阳能电池的光电流、增强光吸收的目的。在本论文中,我们将通过一种热蒸镀法将Au纳米粒子掺杂到反型聚合物太阳能电池的WO_3阳极缓冲层中。由于Au和WO_3之间的表面能的差异,导致蒸镀过程中Au会经历成核,形成孤立岛状结构,金属岛状结构聚集成连续的薄膜这样一个过程。原子力显微镜形貌图表明Au形成薄膜的临界厚度为8nm,这与电流电压特性和光电子转换效率的最优性能测量结果是完全一致的。与未掺杂Au纳米粒子的器件相比,掺杂Au纳米粒子(8nm)器件的能量转换效率从4.67±0.13%显著提高到了6.63±0.17%。此外,透射光谱和稳态光致发光图谱很好的证明了器件光吸收的增强。因此,器件在光学和电学方面性能的改善都意味着利用热蒸镀方法可以进一步提高器件性能,为以后的研究提供了更多的方法和途径。在实验中,通常会将金属纳米颗粒的表面等离子体共振效应有效的应用于聚合物太阳能电池中以提高功率转换效率。然而,这样的实验探究普遍性的集中在利用单一类型的金属纳米粒子来增强仅在特定的窄波长范围内的光吸收。本文中,提出了采用热蒸镀法的表面能量诱导的双金属纳米粒子的等离子体共振,以在更宽的范围内实现光吸收的增强。实验中,通过接触角图像可以得到Ag、Au和WO_3之间的表面能差异,这使得Ag和Au在蒸镀过程的初始阶段会分别聚集成孤立的岛状结构而不是立即成膜,这一点在AFM图谱中也得到了清晰的证明。由于Ag(350-450nm)和Au(450-600nm)纳米粒子诱导的等离子体激元增强波长范围几乎可以覆盖活性层的整个吸收光谱,它们协同作用使得器件的能量转换效率从4.57±0.16提高到了6.55±0.12%。此外,稳态PL测试有力的说明了Ag、Au纳米粒子诱导的局域表面等离子体共振效应可以有效的提高光吸收的强度。最后,紫外光电子能谱揭示出,在缓冲层中掺杂Au和Ag纳米粒子会引起WO_3功函数和价带的上移,这与空穴收集能力直接相关。我们相信利用简单的热蒸镀技术的表面能诱导的双金属纳米粒子局域等离子体共振效应可以为聚合物太阳能电池的能量转换效率提高更大的发展空间。
[Abstract]:Polymer solar cells due to its light weight, low cost, flexible and other unique and traditional inorganic thin film solar cell formed fierce competition. In the past few years, the research on polymer solar battery has penetrated into all aspects, including synthesis, electron donor and acceptor materials interface modification nano particles, doped, light trapping method, series structure, which makes the energy conversion efficiency of polymer solar cells has more than 10%.. However, compared with inorganic solar cells, the energy conversion efficiency of polymer solar cells is relatively low, limiting its further development and application. From the basic principle of polymer solar cells the point of view, the external quantum efficiency is determined by the internal quantum efficiency and absorption efficiency of the product. Although many polymer materials with high The absorption coefficient (105cm-1), but compared with the relative band gap of silicon material with high polymer material, is still difficult to absorb enough light for solar cells. Therefore, in order to enhance the light absorption device without increasing the thickness of the active layer of the polymer solar cells to produce a light trapping method (or light management). At present, various light harvesting methods have been widely used, including micro cavity structure, photonic crystal and plasma nano structure. In these methods, in particular the plasmon optical properties based on nano structure, because of its unique characteristics of tunable optical resonance and attract a lot of attention. In the experiment, through the plasma resonance to improve the photocurrent of polymer solar cells, enhance light absorption. In this thesis, we will go through a heat Evaporation method with Au nanoparticles doped WO_3 anode buffer layer anti type polymer solar cell. Because of the differences between the surface Au and WO_3 can lead to the evaporation process, Au undergoes nucleation, formation of isolated island structure, metal island structure poly film integrated continuous atomic force of such a process. Microscope shows the critical thickness of Au thin film formation is 8nm, the optimal performance measurement results and the current voltage characteristics and photoelectric conversion efficiency is exactly the same. Compared with the undoped device of Au nanoparticles doped Au nanoparticles (8nm) energy conversion efficiency of the device from 4.67 + 0.13% to 6.63 + 0.17%. increased significantly in addition the transmission spectra, photoluminescence spectra and steady state is proved to enhance the light absorption of the device. Therefore, the performance of devices in the optical and electrical aspects of the improvement means plating method can further use of steam To improve the performance of the device, provides more methods and approaches for future research. In the experiment, usually applied to surface plasmon resonance of metal nanoparticles effectively in polymer solar cells to improve power conversion efficiency. However, this experiment focused universal in the use of a single type of metal nanoparticles to enhance only in a narrow wavelength in a certain range of light absorption. In this paper, the bimetallic nanoparticles surface plasmon resonance energy by thermal evaporation induced, in order to achieve the enhancement of light absorption in a wide range. In the experiment, the image can be obtained by the contact angle between Au and Ag, the surface of WO_3 the differences, which makes the Ag and Au were gathered in isolated island structure in the initial stage of deposition of the film is not immediately, this point in AFM map has also been clear Proof. Since Ag (350-450nm) and Au (450-600nm) nanoparticles plasmon induced enhancement of the wavelength range can cover almost the whole active layer absorption spectra, their synergistic effect makes up to 6.55 + 4.57 + 0.16 from 0.12%. in addition to improve the energy conversion efficiency of the device, the steady-state PL test strongly suggests that Ag, localized surface plasmon the resonance effect induced by Au nanoparticles can effectively improve the light absorption intensity. Finally, ultraviolet photoelectron spectroscopy reveals that in doped buffer layer of Au and Ag nanoparticles can cause the work function of WO_3 and the valence band shift, this ability is directly related with the hole collecting. We believe that we can double metal nanoparticles localized plasmon resonance effect using simple the steam surface plating technology for polymer solar cells can induce the energy conversion efficiency of greater development space.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM914.4

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