Determination of Thickness and Optical Constants of ZnO Thin Films Prepared by Filtered Cat.pdf

CHIN.PHYS.LETT. Vol. 25, No. 2 (2008) 743 Determination of Thickness and Optical Constants of ZnO Thin Films Prepared by Filtered Cathode Vacuum Arc Deposition 1 2 3 1 WANG Ming-Dong() , ZHU Dao-Yun() , LIU Yi() , ZHANG Lin() , 1 1 1∗∗ 1 ZHENG Chang-Xi( ) , HE Zhen-Hui() , CHEN Di-Hu() , WEN Li-Shi () 1State Key Laboratory of Optoelectronic Materials and Technologies, and Department of Physics, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 2Experiment Center, Guangdong University of Technology, Guangzhou 510090 3 School of Physical Science, Shenzhen University, Shenzhen 518060 (Received 4 April 2007) ZnO thin films are prepared on glass substrates by filtered cathode vacuum arc (FCVA) deposition technique. A new method is demonstrated to extract the refractive index, thickness and optical band gap of ZnO thin films from the transmission spectrum alone. The refractive index is calculated from the extremes of the interference fingers. The transmission spectrum is divided into two terms, non-interference term and interference effect term. The thickness of thin films is calculated by simulating the interference term, and the non-interference term is used to calculate optical band gap with the gained thickness. The results are compared with measurements by using an ellipsome