1. D. K. Ghosh and G. C. Bhar, Indian J. Appl. Phys. Part B,54B, 88(1980).
2. Japanese Patent No. 80 21,456; Nippon Telegraph and Telephone Public Corp., June 10, 1980.
3. L. C. Burton and L. H. Slack, Progress Report DOE/ET/23007-4, Virginia Polytechnic Institute and State University (1980).
4. M. A. Littlejohn, Solar Energy Research Institute Technical Report No. SERI/TP-49-105 (North Carolina State University, 1979).
5. J. L. Shay and J. H. Wernick,Ternary Chalcopyrite Semiconductors; Growth, Electronic Properties and Applications, Pergamon Press (1975).