Hydrogen Incorporation in Diamond: The Nitrogen-Vacancy-Hydrogen Complex

Abstract

We report the identification of the nitrogen-vacancy-hydrogen complex in a freestanding nitrogen-doped isotopically engineered single crystal diamond synthesized by chemical vapor deposition. The hydrogen atom is located in the vacancy of a nearest-neighbor nitrogen-vacancy defect and appears to be bonded to the nitrogen atom maintaining the trigonal symmetry of the center. The defect is observed by electron paramagnetic resonance in the negative charge state in samples containing a suitable electron donor (e.g., substitutional nitrogen N(0)(S)).

Importance of Quantum Tunneling in Vacancy-Hydrogen Complexes in Diamond

“…The experimental electron paramagnetic resonance (EPR) data indicates a defect complex with C 3v symmetry, and a model in which the H bonds to the N atom has been proposed [3]. However, ab initio theory in which the H nuclei are treated classically predicts an equilibrium structure in which the H bonds to one of the three unsaturated C atoms at the vacancy [4], giving a defect of C 1h symmetry in clear contradiction with experiment.…”

“…The hydrogen hyperfine parameters for this minimum energy structure, and for the bond length of Ref. [3] are compared to experiment in Table I.…”

“…The static N-V-H ÿ defect proposed by Glover et al [3] has the H atom bonded to the N with a bond length of 1.0 Å . One of the difficulties with this model is that one would not expect the H and N to form a bond at all in these circumstances.…”

“…Figure 1 shows the static nitrogen-bonded model of Ref. [3] and dynamic models for the N-V-H ÿ defect.…”

“…In particular, hydrogen has been identified in complexes with other contaminant defects (e.g., nitrogen) and native defects (e.g., vacancies). For example, the nitrogenvacancy-hydrogen (N-V-H) complex has been reported and investigated, leading to proposed models of the microscopic structure of the complex [3,4].…”