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- Sun, J. W., et al.
(författare)
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Combined effects of Ga, N, and Al codoping in solution grown 3C-€“SiC
- 2010
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 108:1, s. 013503-1-013503-10
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Tidskriftsartikel (refereegranskat)abstract
- We report on Ga-doped 3C–SiC epitaxial layers grown on on-axis (0001) 6H–SiC substrates using the vapor-liquid-solid technique and different melts. The resulting samples have been investigated using secondary ion mass spectroscopy(SIMS), micro-Raman spectroscopy and, finally, low temperature photoluminescence (LTPL) spectroscopy. From SIMS measurements we find Ga concentrations in the range of , systematically accompanied by high nitrogen content. In good agreement with these findings, the spectra show that the Ga-doped samples are -type, with electron concentrations close to . As expected, the LTPL spectra are dominated by strong N–Ga donor-acceptor pair (DAP) transitions. In one sample, a weak additional N–Al DAP recombination spectrum is also observed, showing the possibility to have accidental codoping with Ga and Al simultaneously. This was confirmed on a non-intentionally doped 3C–SiC (witness) sample on which, apart of the usual N and Al bound exciton lines, a small feature resolved at 2.35 eV comings from neutral Ga bound excitons. Quantitative analyses of the DAP transition energies in the Ga-doped and witness sample gave 346 meV for the optical binding energy of Ga acceptors in 3C–SiC against 251 meV for the Al one. The conditions for the relative observa-tion of Ga and Al related LTPL features are discussed and the demonstration of room temperature luminescence using Ga doping is done.
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| 2. |
- Sun, J. W., et al.
(författare)
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LTPL Investigation of N-Ga and N-Al Donor-Acceptor Pair Spectra in 3C-SiC Layers Grown by VLS on 6H-SiC Substrates
- 2010
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Ingår i: Silicon Carbide and Related Materials 2009. ; , s. 415-418
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Konferensbidrag (refereegranskat)abstract
- Ga-doped 3C-SiC layers have been grown on on-axis 6H-SiC (0001) substrates by the VLS technique and investigated by low temperature photoluminescence (LTPL) measurements. On these Ga-doped samples, all experimental spectra collected at 5K were found dominated by strong N-Ga donor-acceptor pair (DAP) transitions and phonon replicas. As expected, the N-Ga DAP zero-phonon line (ZPL) was located at lower energy ( 86 meV) below the N-Al one. Fitting the transition energies for the N-Al close DAP lines gave 251 meV for the Al acceptor binding energy in 3C-SiC and, by comparison, 337 meV for the Ga acceptor one.
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