Vanadium doping of 4H SiC from a solid source: Photoluminescence investigation

Koshka, Yaroslav; Mazzola, Michael S.; Yingquan, S.; Pittman, Charles U.

doi:10.1007/s11664-001-0019-x

Cited by 5 publications

(15 citation statements)

References 11 publications

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“…the polarization of Nb 0 , Nb 1 , and Nb 2 in Fig. 2) we notice that the transition 56 → 56 associated with Nb 1 polarized parallel to the c axis (E c) is strong, but the transition between 4 and 56 states which are allowed in E ⊥ c polarization are either very weak, or not observed at all, because these transitions require spin flip.…”

Section: B Selection Rules For the Optical Transitionsmentioning

confidence: 91%

“…The resulting symmetry of the bound-exciton states is described by representations which are a direct product of the representation for Nb − (fully symmetric, 1 , or A 1 ) and one of the representations for the hole ( 4 or 56 ), i.e., just the same as that of the hole alone. At this point we do not know which of the three possible hole (and therefore exciton) states is lowest in energy (one of the two 4 states or the 56 state), but later we will see that the actual order is 4 , 56 , and 4 in order of ascending energies, with the former two states split by spin-orbit interaction, as depicted schematically in Fig. 3(b).…”

Section: B Selection Rules For the Optical Transitionsmentioning

confidence: 95%

“…The orbital angular momentum associated with an e state will couple to the spin of the hole, which results in spin-orbit splitting into 4 and 56 states (analogous to the spin-orbit splitting for a weakly bound hole just considered). However, we will show that the splitting for a tightly bound hole can be assumed much smaller than that for a free (or weakly bound) hole and it may well be unresolvable in our experiments, i.e., within the line width of the observed PL lines, so that the ground state behaves as a single level.…”

Section: B Selection Rules For the Optical Transitionsmentioning

confidence: 96%

“…3(b) are in very good agreement with the experimental data presented so far. The possible origin of the remaining Nb 3 , Nb 4 , and Nb 5 lines will be discussed later.…”

Section: B Selection Rules For the Optical Transitionsmentioning

confidence: 97%

“…the spectra at zero field in Sec. IV), because the strong Nb 4 line polarized E c is completely suppressed.] However, Nb 5 is clearly visible in The photon energies and wavelengths of the Nb-related transitions in 4H and 6H SiC are summarized in Table I together with their polarization.…”

Section: B Temperature Dependence and Ple Spectroscopymentioning

confidence: 98%

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Optical properties and Zeeman spectroscopy of niobium in silicon carbide

et al. 2015

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The optical signature of niobium in the low-temperature photoluminescence spectra of three common polytypes of SiC (4H, 6H, and 15R) is observed and confirms the previously suggested concept that Nb occupies preferably the Si-C divacancy with both Si and C at hexagonal sites. Using this concept we propose a model considering a Nb-bound exciton, the recombination of which is responsible for the observed luminescence. The exciton energy is estimated using first-principles calculation and the result is in very good agreement with the experimentally observed photon energy in 4H SiC at low temperature. The appearance of six Nb-related lines in the spectra of the hexagonal 4H and 6H polytypes at higher temperatures is tentatively explained on the grounds of the proposed model and the concept that the Nb center can exist in both C 1h and C 3v symmetries. The Zeeman splitting of the photoluminescence lines is also recorded in two different experimental geometries and the results are compared with theory based on phenomenological Hamiltonians. Our results show that Nb occupying the divacancy at the hexagonal site in the studied SiC polytypes behaves like a deep acceptor.

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Section: B Selection Rules For the Optical Transitionsmentioning

confidence: 91%

Section: B Selection Rules For the Optical Transitionsmentioning

confidence: 95%

Section: B Selection Rules For the Optical Transitionsmentioning

confidence: 96%

“…3(b) are in very good agreement with the experimental data presented so far. The possible origin of the remaining Nb 3 , Nb 4 , and Nb 5 lines will be discussed later.…”

Section: B Selection Rules For the Optical Transitionsmentioning

confidence: 97%

Section: B Temperature Dependence and Ple Spectroscopymentioning

confidence: 98%

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Optical properties and Zeeman spectroscopy of niobium in silicon carbide

et al. 2015

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Effect of high-temperature processing on the creation of boron-related deep levels in 4H-SiC

Das

Koshka

Mazzola

et al. 2006

J. Electron. Mater.

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High-temperature processing was applied to SiC boron-doped epitaxial layers, epitaxial layers grown on boron-rich substrates, and boron-implanted samples in order to establish conditions favorable for the formation of boron-related centers (D-centers) that introduce a deep level in SiC bandgap. Photoluminescence (PL) was used to detect and compare the formation of the D-center after different processing steps. It was confirmed that the presence of lattice defects was required for achieving significant boron diffusion and D-center formation. In addition, epitaxial growth on the top of a boron-implanted sample yielded efficient boron in-diffusion in the growing layer, which resulted in a material compensated with D-centers. The temperature dependence of the D-center formation efficiency was investigated.

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