Radiative recombination in phosphorus-doped CVD diamond

Abstract

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 nophonon (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 10 17 cm -3 to ≈ 10 19 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.

Determination of the phosphorus content in diamond using cathodoluminescence spectroscopy

“…The spectrum of the phosphorus-BE is more complex: The TO, TA, and no-phonon ͑NP͒ assisted recombinations with maxima respectively at 5.19, 5.24 and 5.33͑5͒ eV present a triplet fine structure-labeled a, b, c-characteristic of phosphorus and recently evidenced in high quality phosphorus-doped diamond. 15 As seen in Fig. 1, this structure is more clearly resolved in the case of the NP recombination with linewidths down to 3.2 meV.…”

“…12 Simultaneously, the optical properties of phosphorus-doped diamond have been investigated. [13][14][15] However, the graphs from which the phosphorus content in diamond can be deduced from a simple cathodoluminescence ͑CL͒ spectrum have not been reported.…”

Phosphorus donor incorporation in (1 0 0) homoepitaxial diamond: Role of the lateral growth

“…(1 0 0) and (1 1 1), respectively, indicating the good cristallinity of the phosphorus-doped layers [31]. As a result, the properties of the (1 0 0) and (1 1 1) Fig.…”

Phosphorous Doping of Microcrystalline CVD Diamond Using Modified Conditions

“…Figure 5 displays two CL spectra taken on two P-doped polycrystalline samples with different doping concentration. Two important peaks in the excitonic region are visible in the CL spectra: the free exciton (FE TO ) peak at 5.27 eV and the P-bound exciton (BE TO ) peak at 5.18eV [16]. Both recombination events are assisted with the emission of transverse optic phonons.…”