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内容記述 |
The single-photon source (SPS), a quantum device that can generate single photons on demand, is crucial for the development of quantum communication technologies. Isolated rare earth (RE) ions in semiconductors, whose luminescence transition in the 4f-shell is inherently single photon emission, are a promising candidate for SPS operating at room temperature (RT) because of their stable photon emission with a narrow linewidth even at RT and their potential of electric control (i.e. electroluminescence: EL). In particular, GaN is the suitable host since RE ions do not show significant thermal quenching at RT due to its large bandgap (3.4 eV). Ion implantation technique is used to fabricate electrically driven RE-SPS, ensuring precise RE ion positioning and quantity control. However, limited studies exist on EL characteristics of RE-doped GaN diodes fabricated by ion implantation. Here we show that Pr-doped GaN devices were successfully fabricated through crystal growth, ion implantation, annealing, regrowth, and device fabrication. An-GaN layer was grown on a GaN substrate, followed by Pr ion implantation at 700 keV with a dose of 1×1014 cm−2. Ultra-high-pressure annealing was performed at 1400 °C for 10 min under 1 GPa N2, after which a p-GaN layer was regrown to form a p-n diode. The I-V measurements showed rectifying behavior. However, irradiation-induced defects at the p-n junction generated by ion implantation caused an increase in series resistance. The EL measurements revealed that a sharp emission peak appeared at 652 nm, which matched the PL emission of Pr3+ in GaN. This fact indicates that the observed EL also originated from the Pr-related transition. Additionally, the I-L characteristics showed a positive correlation between the sharp peak intensity and injection current. These results indicate that the EL in the Pr-doped GaN device is caused by the energy transfer from carrier recombination. |
