【作者】 陈东生；

【导师】 马忠权；

【作者基本信息】 上海大学 ， 凝聚态物理， 2013， 博士

【摘要】 带隙工程的规模化制备及其应用已成为太阳能电池领域关键课题之一。溅射沉积技术适合大面积规模化工业生产，因此，本论文主要围绕如何利用此法制备出具有高质量变带隙的Cu(In_1-xGa_x)Se₂（CIGS）合金薄膜，并对其性质进行深入研究。同时，也系统研究了变带隙形状的特征参数对器件性能的影响。最后，深入研究了如何利用快速热退火工艺改善器件的性能。发展了一种利用CuGa（28at.%）合金靶和In靶作为溅射源，在沉积过程中，通过控制沉积温度、旋转速率、沉积率和时间来控制CIGS薄膜中的Ga/（In+Ga）的比率的制备工艺；并成功制备出具有不同梯度带隙的CIGS电池。对于具有“”形带隙的CIGS电池，其最优性能参数为：J_SC=24.3mA/cm2，V_oc=600mV，FF=60.5%，Eff=8.83%。对于具有“V”型带隙的CIGS电池，其最优性能参数为：J_SC=26.8mA/cm2，V_oc=630mV，FF=72.1%，Eff=12.1%。对于具有不合理“V”型带隙的亚稳定态CIGS电池，探索了一种利用快速热退火（RTA）对其进行调制的工艺。在300度的低温下，可以将带隙优化到一个合理的水平，并可将电池的效率提高1-2%。建立了一种利用X射线光电子能谱（XPS）与卢瑟福背散射（RBS）相结合研究“V”型带隙的CIGS电池界面的方法。结果显示：对于“V”型带隙的CIGS电池，其结构可以分为如下九层：AZO/ZnO/界面混合层/CdS/界面混合层/CIGS1/CIGS2/MoSe₂/Mo。发展了一种适用于大面积生产的电极制备工艺：丝网印刷。通过低温浆料将用于硅基的前电极制备工艺移植到CIGS电池中。系统研究了浆料的不同成份，烘干温度、时间等参数对电池性能的影响。同时，比较了真空蒸发与丝网印刷两种电极制备方法对CIGS电池性能和稳定性的影响。系统研究了RTA对CIGS电池性能影响的机制。RTA能有效消除CIGS薄膜中的残留Cu2-xSe化合物、提高薄膜的结晶程度、减小前表面的光损失、提高了CdS薄膜对蓝光的响应、增加了前表面的粗糙程度以及减少CIGS层中的缺陷态等。同时，RTA还能优化多层薄膜中原子的组分比以及调整Mo/CIGS界面混合区的厚度。更多还原

【Abstract】 The large-scale fabrication and application of bandgap engineering have becameone of key issues in the field of solar cells. Sputtering deposition techniques aresuitable for large-scale and industrial production. Therefore, this paper mainlyfocuses on how to prepare high quality Cu(In_1-xGa_x)Se₂（CIGS） alloy films withvariable bandgap by using sputtering technique. And the properties of these filmsare deeply studied. Meanwhile, the effects of the characteristics parameters withdifferent bandgaps profile on the device performances are also systematicallyresearched. Finally, it is studied how to use rapid thermal annealing （RTA） processto improve device performance.By adjusting deposition temperature, rate of rotation, the deposition rate and time tocontrol the ratio of Ga/（In+Ga） during the deposition process, we successfullyfabricated the CIGS solar cell with variable band gap by using Cu-Ga （28at.%） alloytarget and an In target acting as sputtering source. For the CIGS solar cell with the“” grading profile, the optimal opto-electric conversion efficiency of8.83%(J_SC=24.3mA/cm2,V_oc=600mV, FF=60.5%) is obtained. For the solar cell with the“V” grading profile, the optimal opto-electric conversion efficiency of12.1%(J_SC=26.8mA/cm2,V_oc=630mV,FF=72.1%) is obtained under AM1.5G.The interfaces characteristics of CIGS cells with “V” profile are studied by theapproach combined X-ray photoelectron spectroscopy （XPS） with Rutherford backscattering （RBS）. The results showed that its structure can be divided into nine layerssuch as AZO/ZnO/Interface Mixed layer/CdS/Interface mixed layer/CIGS1/CIGS2/MoSe₂/Mo.Screen printing suitable for large scale and industrial production is developed toprepare front electrode of CIGS solar cells. The front electrode fabriation process insilicon solar cells is transplant into CIGS solar cells by low temperature slurry. Theeffects of different components, drying temperature and time parameters in slurry on the device performance are systematically studied. At the same time, we compare theeffect of vacuum evaporation on CIGS solar cell performance and stability withscreen printing.The impact mechanism of RTA on CIGS device performance is systematicallystudied. RTA can effectively eliminate the residual Cu2-xSe compounds in CIGS thinfilm，improve the crystallinity of the thin film, reduce the light loss of front surface,improve the CdS film on the blue response, increase the roughness of the frontsurface and reduce the defect states in CIGS layer. Meanwhile, RTA also optimizesthe atomic composition ratio in the multilayer film and adjusts the mixing zone atMo/CIGS interface.更多还原