Luminescence Spectroscopy of Bound Excitons in Diamond

Abstract

Since the research on diamond doping remains an issue for electronic applications, the luminescence spectroscopy of bound excitons appears essential to evaluate the properties of shallow dopants in diamond. In this paper, the formation and recombination processes of bound excitons in diamond are reviewed for boron acceptors, phosphorus, and arsenic donors. Pulsed and continuous excitations are considered, the latter being currently used for the measurement of donor and acceptor concentrations in diamond.

Quantitative relevance of substitutional impurities to carrier dynamics in diamond

“…However, methods for evaluating nitrogen at parts-per-billion (ppb) levels below the SIMS detection limits are not common 2 . On the other hand, the quantification method for boron impurities by cathodoluminescence 5 has been recently extended with the detection limit below 0.05 ppb 6,7 . Because of the long-term difficulty of doping control and the quantification problem, capture cross sections of carriers or excitons at impurities in diamond have been missing parameters for 20 years 8,9 . In this study, we have performed electronparamagnetic-resonance measurements to determine concentrations of substitutional nitrogen down to subppb levels.…”

Radiative lifetime of boron-bound excitons in diamond

“…The localization energy E loc of excitons at boron impurities in diamond is as high as 49 meV. 12 Up to now, the luminescence properties of boron-bound excitons in diamond have been discussed only on the basis of CL measurements. 13,14 No absorption spectra have been measured so far, which hindered unveiling the basic optical constants such as radiative lifetimes needed for the optoelectronic applications.…”

“…Interestingly, the radiative lifetime of free excitons s F rad can be derived by using the sensitivity factor s ¼ s F rad g lum rv th introduced previously for the measurements of impurity concentrations by CL. 12 With r ¼ 4 Â 10 À14 cm 2 , the free-exciton capture cross-section at neutral-boron impurities 23 enhancing the radiative recombination rate. Finally, the optical constants deduced in this work give a full understanding of the impurity quantification using the ratio of luminescence intensities between free and bound excitons in diamond.…”

Combining nanostructuration with boron doping to alter sub band gap acceptor states in diamond materials

“…As B:PCD-H and B:Dfoam-O contain numerous grain boundaries, 32 based on the theoretical calculations it is therefore reasonable to assert that presence of B atoms near the grain boundaries induce defects at these non-terminated surfaces resulting in the high intensity peaks attributed to surface excitonic states. However, in case of B:Dfoam-H the defect states that are predominantly present at the surface of the crystallites are completely saturated upon hydrogenation [62][63][64] resulting in the absence of states A and B at the H-terminated surfaces as validated by theory calculations. Similar observation was reported by Barjon et al based on cathodoluminescence measurements.…”