Prominent luminescence of silicon-vacancy defects created in bulk silicon carbide p–n junction diodes

Abstract

We investigate fluorescent defect centers in 4H silicon carbide p–n junction diodes fabricated via aluminum-ion implantation into an n-type bulk substrate without the use of an epitaxial growth process. At room temperature, electron-irradiated p–n junction diodes exhibit electroluminescence originating from silicon-vacancy defects. For a diode exposed to an electron dose of $$1 \times 10^{18}\,{{\mathrm{cm}}}^{-2}$$ 1 × 10 18 cm - 2 at $$800\,{{\mathrm{keV}}}$$ 800 keV , the electroluminescence intensity of these defects is most prominent within a wavelength range of 400–$$1100\,{{\mathrm{nm}}}$$ 1100 nm . The commonly observed $${{\mathrm{D}}}_1$$ D 1 emission was sufficiently suppressed in the electroluminescence spectra of all the fabricated diodes, while it was detected in the photoluminescence measurements. The photoluminescence spectra also displayed emission lines from silicon-vacancy defects.

Defect-Induced Luminescence Quenching of 4H-SiC Single Crystal Grown by PVT Method through a Control of Incorporated Impurity Concentration

“…Figure 6b shows the PL spectra of the three types of 4H-SiC crystal samples at extremely low temperatures (T = 50 K). Both N-Al and N-B DAP emissions were observed at 420 and 580 nm, respectively, at extremely low temperatures [30][31][32]. The peak intensity of the N-Al DAP emissions was observed to be the highest in S1.…”

“…All of the samples showed a wide non-Gaussian symmetric peak located at 533 nm that corresponds to the N-B donor-acceptor pair (DAP) emission [22,23]. The peak intensity of the N-B DAP emissions for S2 was observed to be high, resulting in an increase in the N-B DAP density at room temperature (T = 298 K) [30][31][32]. The N-B DAP emissions of S1 were the weakest, although the concentrations of N and B were the highest among the three 4H-SiC crystal samples according to the ICP-OES data in Table 2.…”

“…The N-B DAP emissions of S1 were the weakest, although the concentrations of N and B were the highest among the three 4H-SiC crystal samples according to the ICP-OES data in Table 2. The reason could be that the N-B DAP emissions of S1 were affected by the N-Al DAP emissions at 420 nm [30][31][32]. These luminescence properties are directly correlated with energy-level transitions in semiconductors.…”

“…This type of recombination introduces a complex donor-acceptor recombination mechanism. Thus, the impurity concentration may have a critical influence on the luminescence properties [30][31][32].…”

“…This type of recombination introduces a complex donor-acceptor recombination mechanism. Thus, the impurity concentration may have a critical influence on the luminescence properties [30][31][32]. Figure 6b shows the PL spectra of the three types of 4H-SiC crystal samples at extremely low temperatures (T = 50 K).…”