脉冲激光沉积及硒化法制备Cu(In,Ga)Se2薄膜研究

The study of Cu(In, Ga)Se2 thin films prepared by pulsed laser deposition and selenization

摘要:

采用脉冲激光沉积和硒化后热处理的方法在石英衬底上制备Cu(In,Ga)Se2（简写为CIGS）薄膜，研究脉冲激光沉积（PLD）技术在制备CIGS薄膜太阳能电池材料上的应用，分析了不同预制层沉积顺序及厚度对CIGS薄膜组织结构、表面形貌、成分以及光学性能的影响。实验结果表明：(1)利用PLD技术及后硒化处理的工艺，制得的CIGS太阳能电池吸收层具有纯相和高结晶度等特性；(2)CuGa/In金属预制层的叠层顺序和叠层数、硒化退火温度对薄膜的结晶质量、晶粒尺寸、成分都具有重要的影响，其中叠层顺序影响最为明显；(3)样品均表现出对可见光区具有透射率低和吸收系数高的光学特性。本工作为制备性能优良的CIGS太阳能电池吸收层，提供了一个新颖的工艺手段。

Abstract:

In this paper, pulsed laser deposition (PLD) is attempted to be an alternative synthesis method for Cu-Ga-In (CIGS) thin films and the application of PLD on CIGS thin film solar cell materials was studied. Cu-In-Ga prefabricated metal films were grown on the quartz substrates by PLD method. Then the CIGS films with different Se content were synthesized by the post-selenization-annealing process. The structure, element component proportion and optical properties of the CIGS films with different deposition orders and thicknesses of the CuGa/In prefabricated metal layers were investigated. The experimental results indicate that, (1) The CIGS solar cell absorption layer with properties such as pure phase and high crystallinity can be obtained by PLD technique and Se-annealing processes. (2) The deposition order and thickness of prefabricated CuGa/In metal layers, as well as the Se-annealing temperature, have great influences on the crystallization, grain sizes and component proportion of the CIGS thin films. Compared to the CIGS film with In/CuGa double-prefabricated layers, the CIGS film with CuGa/In/CuGa trinal-prefabricated layers possesses better crystallization. (3) The prepared CIGS films all present low transmittance and high absorption coefficient in visible light region. Moreover, the largest value of Eg up to 1.21 eV was obtain in the CIGS films, which is higher than that in CuInSe ternary materials, and is benefit for the absorption of the high-energy photons in visible light. This work provided a novel technological method for obtaining the absorption layer of CIGS thin film solar cell with excellent performance.