1. Department of Materials and Optoelectronic Science; National Sun Yat-Sen University; Kaohsiung Taiwan
2. Iron & Steel Research & Development Department, China Steel Corporation; No.1, Zhonggang Rd., Xiaogang Dist. Kaohsiung City 81233 Taiwan, R.O.C
3. Department of Materials and Optoelectronic; National Sun Yat-Sen University; Taiwan, R.O.C.