Splitting of type-I (N-B, P-Al) and type-II (N-Al, N-Ga) donor-acceptor pair spectra in 3C-SiC

Abstract

Discrete series of lines have been observed for many years in donor-acceptor pair (DAP) spectra in 3C-SiC. In this work, the splitting of both type-I (N-B, P-Al) and type-II (N-Al, N-Ga) DAP spectra in 3C-SiC has been systematically investigated by considering the multipole terms. For type-I spectra, in which either N or B substitutes on C sites or P and Al replace Si, the splitting energy of the substructure for a given shell is almost the same for both pairs. For type-II spectra, in which N is on the C site while Al and Ga acceptors replace Si, we find that, when compared with literature data, the splitting energy for a given shell is almost independent of the identity of the acceptor. For both type-I and type-II spectra, this splitting energy can be successfully explained by the octupole term V 3 alone with k 3 = −2 × 10 5Å4 meV. Comparing the experimental donor and acceptor binding energies with the values calculated by the effective-mass model, this suggests that the shallow donor (N,P) ions can be treated as point charges while the charge distribution of the acceptor ions (Al,Ga,B) is distorted in accord with the T d point group symmetry, resulting in a considerable value for k 3 . This gives a reasonable explanation for the observed splitting energies for both type-I and type-II DAP spectra.

Donor–Acceptor Pair Quantum Emitters in Hexagonal Boron Nitride

“…1(b). This radiative recombination of DAPs in semiconductors can generate a series of sharp lines with a broadband distribution in the PL spectra, as reported for other semicondcutors [25][26][27][28][30][31][32][33] . Figure 1(c) shows the typical PL spectrum of single-photon emitters from hBN sample at 4 K. The hBN samples are prepared on SiO2/Si substrate from hBN flakes suspended in 50/50 ethanol/water solution (Graphene Supermarket).…”

“…2(c), indicating the truth of the DAP mechanism here. The unmatched lines can be attributed to the inhomogeneous distribution of the defects and the multipole term 27 . In addition, the crystal structure of the hBN sample may be deformed with strains, which can also lead to small deviations 32 .…”

“…As one of the fluorescence mechanisms, the donor-acceptor pair (DAP) transition between the ionized donors and acceptors has been studied in traditional semiconductors, including silicon 25,26 , silicon carbide 27,28 , diamond 29 and other compound semiconductors [30][31][32][33] . Generally, the DAP transition is characterized by a series of sharp PL lines with a broadband wavelength range at low temperatures [26][27][28][29] .…”

Tailoring the slow light behavior in terahertz metasurfaces

“…There have been a few reports on tailoring the classical analogue of EIT using metamaterials at microwave [32][33][34], terahertz [35][36][37] and optical frequencies [13,38], either by tuning the near field coupling or by changing the material properties. Manipulation of EIT in classical systems will allow us to precisely tailor the group velocity [19,38] and the delay bandwidth product [32] of the transmitted pulse. Moreover, it provides a clear picture of the coupling mechanisms in the classical analogue of EIT, that can help us in drawing the closest analogy between the classical and the quantum systems.…”

“…Later its analogue was extended to the classical systems [27], * ranjans@ntu.edu.sg since then EIT effects have been observed in various classical systems, including metamaterials [13][14][15][16][17][18][19], photonic crystals [28], micro ring resonators [29,30] and all dielectric metasurfaces [31]. There have been a few reports on tailoring the classical analogue of EIT using metamaterials at microwave [32][33][34], terahertz [35][36][37] and optical frequencies [13,38], either by tuning the near field coupling or by changing the material properties. Manipulation of EIT in classical systems will allow us to precisely tailor the group velocity [19,38] and the delay bandwidth product [32] of the transmitted pulse.…”