摘要
目的:退火条件直接影响着电沉积制备的铜铟镓硒薄膜品质,而薄膜品质决定着最终得到器件的转换效率。本实验在不同退火条件下对薄膜进行处理,得出退火条件对薄膜各项表征指标的影响规律,并根据观察到的规律改善退火工艺,以提高铜铟镓硒薄膜品质。创新点:目前利用水溶液电沉积制备的铜铟镓硒薄膜太阳能电池转换效率不高,而退火是制作此电池的关键步骤之一。本文研究了退火温度和升温速率对薄膜品质的影响,分析其可能原因及退火过程发生的反应,并制备出了理想的高品质薄膜。方法:1.在水溶液中利用电沉积法制备出铜铟镓硒薄膜前驱体。2.对前驱体进行退火处理,并针对不同的样品采用不同的退火温度和升温速率。3.利用X射线衍射(XRD)、拉曼光谱(Raman)、扫描电子显微镜(SEM)、X射线荧光光谱(XRF)对薄膜进行表征,分析不同退火条件对结果的影响规律。结论:1.退火温度的影响:退火温度由450°C升高到580°C时,得到的薄膜结晶性越来越好,晶粒边界越来越不明显,Cu/(In+Ga)的比例逐渐升高,说明高温下(≥450°C)金属铟和镓较易挥发;实验中还发现Cu-Se化合物的总含量随退火温度的升高而降低。2.升温速率的影响:退火速率越高,薄膜结晶性越好;快速升温时薄膜中Cu/(In+Ga)的比例略低于慢速升温时的样品,而Ga/(In+Ga)的比例几乎不变,说明快速升温可以减少In和Ga的挥发。
Cu（ln,Ga）Se2 （CIGS） precursor films were deposited on Mo/glass by electrodeposition, and then annealed in Se vapor. The annealing temperature ranged from 450 ℃ to 580 ℃, and two heating rates were selected. The results showed that the crystalline quality of the CIGS films and formation of the Cu-Se compound could be strongly influenced by the selenization temperature and heating rate. Raman spectroscopy and X-ray diffraction （XRD） analysis showed that when the selenization temperature was increased from 450 ℃ to 550 ℃, the amount of binary CuSe phase decreased and the amount of Cu2Se increased. After annealing at 580 ℃, a minimum amount of Cu2-xSe compounds was obtained and the degree of CIGS film crystallinity was higher than in other samples. The relationship between the properties of the film and the heating rate was studied. XRD and Raman spectra showed a decrease in the Cu2-xSe phase with increasing heating rate. Scanning electron microscopy （SEM） and XRD showed a remarkable increase in the grain size of CIGS during rapid heating.
基金
Project supported by the National High-Tech R&D Program(863 Program)of China(No.2015AA034201)
the National Natural Science Foundation of China(No.11474355)
the Chinese Universities Scientific Fund(No.2017LX002)
关键词
铜铟镓硒薄膜
电沉积
退火条件
拉曼光谱
Cu（ln
Ga）Se2（CIGS）thin films
Electrodeposition
Selenization
Raman spectroscopy
