Synchrotron radiation effect on CIS thin films prepared by laser ablation for solar cell application

CuInSe_2及其相关薄膜(CIS薄膜)在光伏能源应用方面引起了人们的极大关注。太阳能电池在宇宙空间的能源生产方面具有优势。然而，在这种严峻的形势下，很少有关于独联体太阳能电池可靠性的报道。本研究采用激光烧蚀方法制备了CIS薄膜，并对其在同步辐射前后的晶体稳定性进行了表征。第一年，我们搭建了由真空室、真空泵和ArF准分子激光器组成的激光烧蚀系统。在暗室中，放置两种二元化合物制成的靶材，并将高能光束(准分子激光)聚焦到靶材上。用X射线衍射仪、扫描电子显微镜和X射线光电子能谱对薄膜的结构进行了表征，薄膜具有密集排列的柱状晶。第二年，样品被放入Spring-8的另一个超高真空室，以便照射同步加速器束。辐照后，薄膜的结晶度再次得到表征。我们还研究了样品的Cu2p-&Gt；3d跃迁的X射线吸收研究。用准分子激光烧蚀法制备的顺式薄膜具有较高的晶体质量和结构稳定性，可用于宇宙太阳能电池的应用。利用X射线光电子能谱(XAFS)测量手段进一步研究了在同步辐射前后的CIS薄膜的电学性质。

CuInSe_2 and its related thin films (CIS thin films) have attracted considerable attention for photovoltaic energy application. Solar cell has an advantage for energy production in cosmic space. However, very few reports have been published for reliability of CIS based solar cell at this severe situation. In this study, CIS thin films were prepared by laser ablation method and characterized crystallographic stability before and after the radiation of synchrotron beam.In the first year we have constructed the laser ablation system which consists of vacuum chamber, vacuum pump, and ArF excimer laser. In the chamber, target made by two binary compounds were placed and high energy beam (excimer laser light) is focused onto it. CIS thin films were deposited and were characterized the structural properties using by XRD, SEM, and XPS.The thin films had densely packed columnar grains. In the next year, samples were set into another ultra high vacuum chamber at Spring-8 in order to irradiate the synchrotron beam. The thin films were characterized crystallinity again, after the irradiation. We also examined x-ray absorption study for Cu 2p->3d transition for the samples. CIS thin films prepared by excimer laser ablation revealed high crystallographic quality and its structural stability would be useful for cosmic solar cell application. Further investigation for electrical properties of the CIS thin films before and after the synchrotron irradiation is necessary using XAFS measurement.