title: Identification of nitrogen defects in diamond with photoluminescence excited in the 160-240 nm region.
abstract: Photoluminescence (PL) spectra of natural diamond powders of type IaAB at 300 and 13 K were excited with synchrotron radiation in the wavelength range of 150-260 nm. The spectral features observed in the excitation spectra at 13 K show four vibrational progressions related to nitrogen defects in diamond: A, B, B', and N3. Progression A has a spacing of 1258 ± 40 cm(-1), associated with the N2 (or A) center; progression B has a spacing of 1181 ± 40 cm(-1) and progression B' has a spacing of 744 ± 40 cm(-1) related to the N4 (or B) center; and progression N3 has a spacing of 1417 ± 40 cm(-1) associated with the N3 center. The PL of these defects comprise continuous emission with two broad lines with maxima of ∼420 and 469 nm at 300 K. Upon excitation with light at wavelengths of <200 nm, the distinct zero-phonon lines of N3 and N4 centers in diamond at a temperature of 13 K become prominent at 416.0 and 491.2 nm, respectively. The vibrational progressions in the photoluminescence excitation (PLE) spectra of N2, N3, and N4 centers in diamond of type IaAB at 13 K are identified for the first time. We suggest the use of PL spectra excited in the region of 160-240 nm to analyze and identify the type of diamond.
authors.affiliation: National Synchrotron Radiation Research Center, No. 101, Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan, Republic of China. hopelu@nsrrc.org.tw
authors.forename: Hsiao-Chi
authors.initials: HC
authors.lastname: Lu
authors.forename: Meng-Yeh
authors.initials: MY
authors.lastname: Lin
authors.forename: Sheng-Lung
authors.initials: SL
authors.lastname: Chou
authors.forename: Yu-Chain
authors.initials: YC
authors.lastname: Peng
authors.forename: Jen-Iu
authors.initials: JI
authors.lastname: Lo
authors.forename: Bing-Ming
authors.initials: BM
authors.lastname: Cheng