Cu-In膜的相结构对CuInSe2薄膜性能的影响

为考察溅射功率对Cu-In薄膜中相结构以及相应的CuInSe2(简称CIS)薄膜性能的影响,采用中频交流磁控溅射方法沉积Cu-In薄膜,并采用固态硒化方法形成CIS薄膜.采用SEM和EDX观察和分析了它们的表面形貌和成分,采用XRD表征了薄膜的组织结构,并分析了硒化中的反应动力学过程.结果表明,在不同的溅射功率条件下,Cu-In预制膜以Cu11In9相或Cu11In9和CuIn的混合相存在.由Cu11In9和CuIn混合相薄膜形成的CIS薄膜具有单一的CuInSe2相黄铜矿相结构,且其成分接近CuInSe2化学计量比.而由Cut1In9相Cu-In预制膜形成的CIS薄膜中除了CuInSe2相以外,还出现了Cu2Se相,且其成分远离CuInSe2化学计量比.因此,具有Cu11In9和CuIn混合相结构的CuIn薄膜更适合制备CIS太阳电池吸收层.

Effects of Cu-In precursor film phase structure on CuInSe2 film properties

The effect of sputtering power on the phase structures of Cu-In precursors and the properties of CuInSe_2 (CIS) films were investigated. Cu-In precursors prepared using a middle frequency AC magnetron at different sputtering powers. CuInSe_2 films were formed by selenization in a selenium atmosphere. SEM and EDX were used to observe the surface morphologies and to determine the atomic concentrations in both the Cu-In precursors and the CIS films. Their microstructures were characterized by XRD. The kinetics of the reactions in the film were also analyzed. The results show that the Cu-In precursors are mainly composed of a Cu_11In_9 phase with or without a CuIn phase depending on the sputtering power. Stoichiometric CIS films with a single chalcopyrite phase were synthesized from Cu-In precursors containing the Cu_11In_9 phase and the CuIn phase. The Cu_2Se phase occurs in addition to the CIS chalcopyrite phase in Cu-rich CIS films formed using a Cu-In precursor with the Cu_11In_9 phase. The Cu-In precursor with Cu_11In_9 and CuIn phases is favorable for CuInSe_2 absorbers in solar cells.