Identification of the Nitrogen Interstitial as Origin of the 3.1 eV Photoluminescence Band in Hexagonal Boron Nitride

Abstract

Nitrogen interstitials (N${}_{\mathrm{i}}$) have the lowest formation energy among intrinsic defects of hexagonal boron nitride (hBN) under n-type and N-rich conditions. Using an optimized hybrid functional, which reproduces the gap and satisfies the generalized Koopmans condition, an N${}_{\mathrm{i}}$ configuration is found which is lower in energy than the ones reported so far. The (0/-) charge transition level is also much deeper, so N${}_{\mathrm{i}}$ acts as a very efficient compensating center in n-type samples. Its calculated photoluminescence (PL) at 3.0 eV agrees well with the position of an N-sensitive band measured at 3.1 eV. It has been also found that the nitrogen vacancy (V${}_{\mathrm{N}}$) cannot be the origin of the three boron electron (TBC) electron paramagnetic resonance (EPR) center and in thermal equilibrium it cannot even exist in n-type samples.

7 pager, 3 figures

References in corpus (3)

• Defect-related photoluminescence of hexagonal boron nitride
• Carbon dimer defect as a source of the 4.1 eV luminescence in hexagonal boron nitride
• Photoluminescence properties of pyrolytic boron nitride

Cited by in corpus (1)

• First principles theory of the nitrogen interstitial in hBN: a plausible model for the blue emitter