Photoluminescence has been studied in Cu diffusedn andp-InP. Inp-InP a Cu related photoluminescence (PL) band was observed at 1·216eV. The temperature dependence of line-width was studied and line-shape and line-width analysis carried out. The configuration coordinate diagram of the band was calculated which showed a small lattice relaxation of 0·079 Å.
Inn-InP two PL bands at 1·20 and 1·01 eV were found at 10 K. The former was similar to the 1·216eV band inp-InP. The PL of the 1·01 eV band was also studied in detail and the corresponding configuration coordinate diagram derived.