胶体PbSe量子点太阳能荧光聚集器的仿真研究

发布时间：2018-01-12 08:06

本文关键词：胶体PbSe量子点太阳能荧光聚集器的仿真研究　出处：《吉林大学》2015年硕士论文　论文类型：学位论文

【摘要】：太阳能荧光聚集器（LSC）是一种聚光型太阳能光伏器件，它可以通过等效聚光的方法，以相对简单的结构代替大面积造价昂贵的太阳能电池，达到降低太阳能光伏发电成本的目的。过去，研究人员经常选用有机荧光材料作为LSC的荧光材料，但它们的光谱吸收范围小，自吸收严重，稳定性差，荧光寿命短，这很大程度上限制了LSC效率的提高。半导体量子点作为近年来备受关注的热点材料，相比于传统有机荧光材料，具有更优异的光学特性，如光谱可调谐，荧光量子效率高，自吸收弱，稳定性好，荧光寿命长等。因此，为了进一步提高LSC的性价比，本文将2.8nm的胶体PbSe量子点引入到LSC的应用中。本文首先分析了半导体量子点的激子能级结构，采用有限深势阱模型与有效质量近似理论相结合的方法，建立了半导体量子点能级结构的计算公式，并对不同尺寸的胶体PbSe量子点的禁带宽度进行了理论计算，发现理论计算值与实验测定值相差不多。然后采用Yu的合成方法合成了不同尺寸的胶体PbSe量子点，，对其进行了TEM、XRD分析，观测到其近似于球形的外形和体岩盐对称的晶体结构，测量了其吸收光谱和PL光谱，发现其第一激子吸收峰和发射峰是尺寸依赖的，并测量得到其荧光量子效率在80%以上。接下来本文详细分析了LSC的工作原理，包括光子在LSC内的转换过程，荧光在LSC内部的传输模式，自吸收和再激发原理，荧光的传输损耗原理等，并根据其工作原理建立了LSC的数学模型。根据该数学模型，用C++编程语言在MicrosoftVisual C++6.0编译器上编写了太阳能荧光聚集器的仿真软件。最后，本文将2.8nm的胶体PbSe量子点应用到LSC中，根据实验测量及查阅资料获得的数据来设定仿真参数，对胶体PbSe量子点太阳能荧光聚集器进行了仿真研究。仿真研究了LSC的尺寸对LSC光电转换效率、几何聚光比和收益参数的影响，得到LSC尺寸的最优值。在最优尺寸下仿真研究了量子点溶液浓度对LSC光电转换效率的影响，得到量子点溶液浓度的最优值。并最终得到了性能优良的LSC，其边长为150cm×200cm，夹层厚度为1mm，量子点溶液浓度为2.5×10-5mol/L，光电转换效率为3.25%，几何聚光比为61.224，收益参数为12.436，说明胶体PbSe量子点可以明显提高LSC的性价比，是用来制作LSC的理想荧光材料。
[Abstract]:Solar fluorescence aggregator (LSC) is a kind of concentrated solar photovoltaic device. It can replace the large area expensive solar cells with a relatively simple structure by equivalent concentrating method. In the past, researchers often choose organic fluorescent materials as LSC fluorescent materials, but their spectral absorption range is small, self-absorption is serious, and stability is poor. The short lifetime of fluorescence greatly limits the efficiency of LSC. Semiconductor quantum dots (QDs), as hot materials in recent years, have better optical properties than traditional organic fluorescent materials. For example, the spectrum is tunable, the fluorescence quantum efficiency is high, the self-absorption is weak, the stability is good, the fluorescence lifetime is long and so on. Therefore, in order to further improve the performance and price ratio of LSC. In this paper, a 2.8 nm colloidal PbSe quantum dot is introduced into the application of LSC. In this paper, the exciton energy level structure of semiconductor quantum dots is analyzed, and the calculation formula of semiconductor quantum dot energy level structure is established by combining the finite deep potential well model with the effective mass approximation theory. The band gap of colloidal PbSe quantum dots with different sizes was calculated theoretically. It was found that the theoretical values were not different from the experimental ones. Then the colloidal PbSe quantum dots of different sizes were synthesized by Yu synthesis method. The spherical shape and the salt symmetry crystal structure are observed. The absorption and PL spectra are measured and the first exciton absorption and emission peaks are found to be dimensionally dependent. The fluorescence quantum efficiency is more than 80%. Then, the principle of LSC is analyzed in detail, including the conversion process of photons in LSC and the transmission mode of fluorescence in LSC. According to the principle of self-absorption and re-excitation, the principle of transmission loss of fluorescence, the mathematical model of LSC is established. The simulation software of solar fluorescence aggregator is programmed with C programming language on MicrosoftVisual C 6.0 compiler. Finally. In this paper, a 2.8nm colloidal PbSe quantum dot is applied to the LSC, and the simulation parameters are set according to the data obtained from the experimental measurement and the reference data. The solar fluorescent aggregator of colloidal PbSe quantum dots is simulated and studied. The effects of the size of LSC on the photoelectric conversion efficiency, geometric concentration ratio and yield parameters of LSC are simulated. The optimal value of LSC size is obtained and the effect of the concentration of quantum dot solution on the photoelectric conversion efficiency of LSC is simulated under the optimal size. The optimum concentration of quantum dot solution was obtained, and the LSCs with good performance were obtained, the side length was 150cm 脳 200cm and the thickness of interlayer was 1mm. The quantum dot solution concentration is 2.5 脳 10 ~ (-5) mol / L, the photoelectric conversion efficiency is 3.25 and the geometric concentration ratio is 61.224, the yield parameter is 12.436. The results show that colloidal PbSe quantum dots can improve the performance / price ratio of LSC and are ideal fluorescent materials for LSC.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM615;O471.1

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