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

Abstract

Nitrogen interstitials (normalNnormali) 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 Koopman's condition, an normalNnormali configuration is found, which is lower in energy than the ones reported so far. The (0/–) charge transition level is also much deeper, so normalNnormali 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 is also found that the nitrogen vacancy (normalVnormalN) cannot be the origin of the three‐boron‐center (TBC) electron paramagnetic resonance (EPR) center and in thermal equilibrium it is even unlikely to exist in n‐type samples.

Substrate Modification during Chemical Vapor Deposition of hBN on Sapphire

“…and Khorasani. , Museur and Kanaev identifies the 3.7 eV peak as a DAP radiative recombination . Khorasani et al has recently elucidated that the nitrogen interstitial (N i ) has the lowest formation energy and therefore provides the most favorable origin of the 3.1 eV peak . An attempt was made to analyze the 3 K PL spectra by Gaussian peak fitting as well, however, it was difficult to unambiguously fit the overall spectra.…”

“…51,52 The 3.7 and 3.1 eV peaks have been seen previously by Museur et al and Khorasani. 53,54 Museur and Kanaev identifies the 3.7 eV peak as a DAP radiative recombination. 53 Khorasani et al has recently elucidated that the nitrogen interstitial (N i ) has the lowest formation energy and therefore provides the most favorable origin of the 3.1 eV peak.…”

“…53 Khorasani et al has recently elucidated that the nitrogen interstitial (N i ) has the lowest formation energy and therefore provides the most favorable origin of the 3.1 eV peak. 54 An attempt was made to analyze the 3 K PL spectra by Gaussian peak fitting as well, however, it was difficult to unambiguously fit the overall spectra. Further studies are needed to understand the origins of the defect peaks with additional experiments or hybrid functional studies.…”

“…Additional peaks can also be resolved around 4.3, 3.7, and 3.1 eV at 3 K. The origin of the 4.3 eV peak is unclear; peaks near that energy has been correlated to the presence of carbon and oxygen impurities in the sample. , The 3.7 and 3.1 eV peaks have been seen previously by Museur et al. and Khorasani. , Museur and Kanaev identifies the 3.7 eV peak as a DAP radiative recombination . Khorasani et al has recently elucidated that the nitrogen interstitial (N i ) has the lowest formation energy and therefore provides the most favorable origin of the 3.1 eV peak .…”

Room temperature deep UV photoluminescence from low dimensional hexagonal boron nitride prepared using a facile synthesis

“…16 Recently, using the Density functional theory (DFT), ab-initio calculations and core level binding energy calculations, the deconvoluted broad XPS spectrum positions were used to assign certain kind of defects in the h-BN lattice. 59,60 Further, there are variety of defects observed in h-BN such as a neutral nitrogen vacancy (V N ), single electron trapped nitrogen vacancy (V N ) −1 , a carbon atom replacing nitrogen (C N ) and some complex defects such as N B V N . [61][62][63] Most of the time, a nitrogen vacancy is either neutral or single occupied (V N ) are predominant in h-BN samples which can be categorised as process induced defect is seen.…”