磁控溅射法制备CIGS薄膜太阳能电池的工艺及性能研究

采用磁控溅射方法直接溅射铜铟镓硒(CIGS)靶材,制备得到了用于太阳能电池吸收层的CIGS薄膜,然后在Se气氛中对该CIGS薄膜进行退火处理。采用扫描电镜、X射线衍射、Raman、XRF、Hall等方法观察和分析了退火的主要工艺参数对薄膜表面形貌、组织结构、成分以及电学性能的影响,并制备了CIGS太阳能电池。结果表明,采用磁控溅射CIGS靶材+Se气氛中退火处理的方法,可以制备得到成分均匀、电学性能优良、单一黄铜矿相的CIGS薄膜;退火温度和退火时间是影响退火后薄膜质量的主要因素。退火温度低于350℃时,退火效果不明显。退火温度在400℃,退火时间达120 min时,薄膜完成再结晶过程,并制得单一黄铜矿相的CIGS薄膜;退火过程存在Cu-Se二次相的析出和消融,同时具有为薄膜补Se的作用。本文采用该方法制备出的CIGS太阳能电池的最高转换效率为7.69%。

Growth and Characterization of Copper Indium Gallium Diselenide Films for Solar Cells Fabrication

The Cu(In1-xGax)Se2(CIGS) films were deposited by magnetron sputtering,followed by post annealing in a mixture of Ar and Se at a reduced atmospheric pressure.The influencing growth factors,including the deposition rate,sputtering power,annealing temperature and annealing time,on electrical properties of the CIGS were evaluated.The microstructures of the CIGS films were characterized with X-ray diffraction,X-ray fluorescence,scanning electron microscopy,and Hall effect spectroscopy.The results show that the post annealing temperature and annealing time strongly affect the stoichiometries,texture,and phase structures of the CIGS films.For instance,after annealing at 400℃ for 120 min,the re-crystallization resulted in copper pyrite phased CIGS films,accompanied by segregation of Cu and Se.Below 350℃,the impact of annealing was non-observable.The prototyped solar cells were fabricated with the CIGS films as the absorption layer,and the highest conversion efficiency was found to be 7.69%.