半导体纳米材料增效晶硅太阳能电池及光电性能研究

发布时间：2018-08-06 11:40

【摘要】：本论文通过化学浴沉积（CBD)、连续离子吸附（SILAR)等方法的方法直接在晶硅片上生长CuO纳米阵列、CuS纳米晶/量子点以及CuO/CuS复合结构材料。并通过X-射线粉末衍射分析仪(XRD),场发射扫描电子显微镜分析仪(FESEM),固体紫外-可见-近红外漫反射光谱分析仪(UV-Vis),半导体材料少数载流子寿命测量仪，光电性能测试等手段测试材料的形貌结构、化学组成、少数载流子寿命及光电转化性能，详细结果如下：合成不同形貌、尺寸的CuO纳米阵列，将其直接沉积在晶体硅片上。CuO纳米阵列/c-Si太阳能电池在250-1250nm范围内，相对于空白晶体硅片显示出极强的光吸收和很低的反射率c-Si太阳能电池结合CuO纳米阵列后，晶体硅片表面到空气之间，能够形成阶梯折射率，从而增加了光捕获。同时，CuO纳米阵列/c-Si结构产生光学共振模型效应，使得入射光能够发生多重散射，极大的增加光了复合结构晶体硅电池对光的吸收利用。同时，P型的CuO纳米阵列沉积在晶体硅片表面后，能有形成CuO纳米阵列/c-Si异质结构并且形成内建电场，这将有利于光生电子-空穴对的有效分离，从而使得少数载流子从空白晶体硅片的5.7哗增加到复合结构的15.0哗。CuO纳米阵列/c-Si结构降低了其光学损失，同时增加了少数载流子的收集，这两方面结合从而极大提高了电池效率。实验结果显示，CuO纳米阵列/c-Si太阳能电池的短路电流，电池效率分别相对提高了10.3%和17.90、CuO纳米阵列/c-Si太阳能电池将有望超过单异质结太阳能电池的Shockley-Queisser局限性。首先在硅片生长CuS纳米晶/量子点，并对其不同形貌，尺寸等进行了较深入的研究和讨论。我们先对硅片进行预处理，即通过腐蚀的方式，使得硅片表面粗化，同时在硅的表面形成Si纳米颗粒。在此基础上，采用连续离子吸附的方法，在硅片表面沉积致密、均匀、牢固的CuS纳米晶/量子点。吸收光谱表明，当CuS纳米晶/量子点生长在硅片表面后，复合结构对光的吸收光谱范围明显变宽，且吸收强度有一定的增加。从最终的结果看，由于CuS纳米晶/量子点具有量子限制效应等特点，能够极大的将光能转化为电能。纳米CuS具有量子限域效应，使禁带宽度增大，当CuS导带与硅片导带接近时，将有利于导带间的电子传递，达到电子输送的结果。而硫化铜本身具有吸收系数高，且多重激子效应使CuS QDs能够将一个光子产生多重电子空穴对，这种多重激子可以使CuS QDs提供比硅片更多的电子，，从而达到提高光电转换效率。此外，我们通过结合CuO纳米阵列的陷光结构并结合CuS纳米晶/量子点的量子效应，在硅片表面首先生长CuO纳米叶，然后再去沉积CuS纳米晶/量子点，与硅片表面N型结构形成串联的PN结异质结构，这种复合结构可以有效的分离电子空穴对，降低光生载流子的结合。而实验结果也证明，CuO/CuS复合结构电池结合了其各自单相结构电池的优点，最终的电池效率从原硅片的9.39%增加到13.0%,相对增加了38%。
[Abstract]:In this paper, by means of chemical bath deposition (CBD), continuous ion adsorption (SILAR) and other methods, CuO nanowire arrays, CuS nanocrystals / quantum dots and CuO/CuS composite structures are directly grown on crystal silicon wafers. The X- ray powder diffraction analyzer (XRD), field emission scanning electron microscope analyzer (FESEM), and solid ultraviolet visible near infrared diffuse. The reflection spectrum analyzer (UV-Vis), the semiconductor material minority carrier life measuring instrument, the photoelectric performance test and so on test the material's morphology, the chemical composition, the minority carrier life and the photoelectric conversion performance, and the detailed results are as follows:
CuO nanoscale arrays of different morphologies and sizes are synthesized, and they are deposited directly on the crystal silicon wafer of the.CuO nanoscale /c-Si solar cell in the 250-1250nm range. Compared with the blank crystal silicon, the strong light absorption and the low reflectivity of the c-Si solar cells are combined with the CuO nanoscale array, and the surface of the crystal silicon wafer surface to the air can be found. At the same time, the CuO nano array /c-Si structure produces optical resonance model effect, which makes the incident light multiple scattering, which greatly increases the absorption and utilization of light in the composite crystal silicon battery. At the same time, the P type CuO nanoscale arrays can form CuO nano after the crystal silicon surface. The /c-Si heterostructure of the rice array and the built in electric field will be beneficial to the effective separation of the photoelectron - hole pair, which makes the minority carrier increase from the 5.7 clam of the blank crystal silicon to the composite structure of the 15 clad.CuO nanoarray /c-Si structure, which reduces the optical loss, and increases the collection of a few carriers at the same time, which are the two aspects. The results show that the efficiency of the battery is greatly improved. The experimental results show that the short circuit current of CuO nano array /c-Si solar cells increases by 10.3% and 17.90 respectively, and the CuO nano array /c-Si solar cells will exceed the Shockley-Queisser limitation of the single heterojunction solar cells.
First, the CuS nanocrystals / quantum dots were grown on the silicon chip, and the different morphology and size were studied and discussed. First, we pretreated the silicon wafer, that is, the surface of silicon was coarsened by corrosion, and Si nanoparticles were formed on the surface of silicon. On this basis, the silicon wafer was used by continuous ion adsorption method. CuS nanocrystalline / quantum dots are deposited on the surface, and the absorption spectra show that when the CuS nanocrystalline / quantum dots grow on the surface of the silicon wafer, the absorption spectrum of the composite structure broadens obviously, and the absorption strength is increased to a certain extent. From the final results, the CuS nanocrystalline / quantum dots have the characteristics of quantum confinement. It can greatly transform the light energy into electric energy. The nano CuS has the quantum confinement effect, which makes the band gap widen. When the CuS guide band is close to the guide band of the silicon, it will be beneficial to the electron transfer between the guide bands and the result of the electron transport. And the copper sulfide itself has a high absorption coefficient, and the multiple exciton effect makes CuS QDs produce more than one photon. With heavy electron hole pair, this multiple exciton can make CuS QDs provide more electrons than silicon chips to improve the photoelectric conversion efficiency. In addition, by combining the trapping structure of the CuO nanoscale array and combining the quantum effects of the CuS nanocrystalline / quantum dots, the first Mr. CuO nanoscale on the surface of the silicon wafer is long, and then the CuS nanocrystalline / quantity is then deposited. A PN junction heterostructure is formed in series with the N type structure on the surface of the silicon wafer. This composite structure can effectively separate the electron hole pairs and reduce the binding of the photogenerated carriers. The experimental results also show that the CuO/CuS composite battery combines the advantages of their respective single-phase structural batteries, and the final battery efficiency increases from 9.39% of the original silicon to 13. .0%, a relative increase of 38%.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM914.4;O649.4

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