铜铟镓铝硒(Cu(InGaAl)Se2)薄膜制备及其光学性能研究

Fabricating Cu(In,Ga,Al)Se2 thin films and studying Ellipsometry and polarized light spectrum on the film

摘要:

本文采用溶剂热法制备出掺铝的铜铟镓硒Cu(InGaAl)Se₂(简称CIGAS)纳米粉末,并直接将此纳米粉末作为蒸镀材料制备铜铟镓铝硒CIGAS薄膜,再将其放置在装有高纯硒粉的自制密封法兰内在真空下进行硒化和退火处理,从而得到符合化学计量比的铜铟镓铝硒CIGAS薄膜。采用X射线衍射(XRD)和拉曼光谱(Raman)以及扫描电镜(STM)观测和能谱(ED)对样品结构和成分进行测量,确认CIGAS薄膜样品是黄铜矿结构和铜铟镓硒成分。采用椭圆偏振光谱测量术对铜铟镓铝硒CIGAS薄膜进行椭偏光谱测量,进而得出薄膜光学参数如折射率n(λ)、消光系数k(λ)、吸收系数以及薄膜光能隙Eg, 并发现Al元素的掺杂明显增加了薄膜光能隙,并进行了相关物理分析。

Abstract:

In this paper, the copper indium gallium aluminum selenium Cu (InGaAl) Se₂(hereinafter referred to as CIGAS) nanometer powders were prepared by the solvent thermal, and the copper indium gallium aluminum selenium CIGAS film was prepared by directly using the nanometer powders as the evaporation materials. And then the amorphous film was placed in homemade sealing flange with high purity selenium powder to selenide and anneal under vacuum, and conform to the stoichiometric ratio of selenium CIGAS copper indium gallium aluminum selenium film. The structure and composition of CIGAS thin films were determined by X-ray diffraction (XRD), Raman spectroscopy (Raman), scanning electron microscopy (STM) and energy spectrum (ED). The elliptic parameters Ψ(λ) and Δ (λ) of copper indium gallium aluminum selenium CIGAS film were measured using elliptic polarization spectral measurement technique, and then the thin film optical parameters such as refractive index n (λ), extinction coefficient k (λ), absorption coefficient and the film’s light energy gap Eg were obtained , and it was found that the doping of Al significantly increases the light energy ga Eg, and the related physical questions were analyzed too.