Radiative recombination in phosphorus-doped CVD diamond

Recently published data have shown that state‐of‐the‐art phosphorus‐doped homoepitaxial CVD diamond layers exhibit ‘perfect’ bound exciton cathodoluminescence (CL) spectra with a triplet of narrow no‐phonon (NP) transitions accompanied by four well resolved wavevector‐conserving phonon replicas. Here, we complement these experimental data demonstrating in particular that this superior quality of the CL spectra is highly reproducible for doping concentration from below 1017 cm–3 to ≈ 1019 cm–3. In a comparison with shallow bound excitons in silicon we address the radiative quantum efficiency of the exciton luminescence and find that P‐bound exciton emission in diamond is less efficient than that from B‐bound excitons. Also discussed are the different intensity ratios of NP‐to‐TO‐phonon transitions for P‐ and B‐bound excitons. Finally the rich finestructure in the exciton spectra is considered and compared to similar finestructure appearing in other near‐bandedge bound exciton luminescence spectra in diamond. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)