STRONG EXCITONIC RECOMBINATION RADIATION FROM HOMOEPITAXIAL DIAMOND THIN-FILMS AT ROOM-TEMPERATURE

We have observed strong emission lines at 5.27 and 5.12 eV at room tem perature in cathodoluminescence spectra from homoepitaxial diamond fil ms grown by step-flow mode prepared with microwave plasma assisted che mical vapor deposition. The temperature dependence of integrated inten sity of the emission lines indicates that they are attributed to free- exciton recombination radiation associated with a transverse optical p honon and its replica. These results have demonstrated the superior cr ystalline quality of the homoepitaxial diamond films grown by the step -flow mode. (C) 1998 American Institute of Physics.