1. Park, Y.S., Chung, C.H. Appl. Phys. Letters 16, 99 (1971)
2. Park, Y.S., Shin, B.K. J. Appl. Phys. 45, 1444 (1974)
3. Chung, C.H., Yoon, H.W., Kang, H.S. and Tai, C.H. Proc. 4th Int. Conf. on Ion Implantation, p. 253 (1974)
4. Aven, M., and Woodbury, H.H. Appl. Phys. Letters 1, 53 (1962)
5. Holton, W.C., de Wit, M., and Estle, T.L. Int. Symp. on Luminescence, p. 454, Munich 1965