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Full-Text Articles in Physics
Enhanced Luminescence Efficiency In Eu-Doped Gan Superlattice Structures Revealed By Terahertz Emission Spectroscopy, Fumikazu Murakami, Atsushi Takeo, Brandon Mitchell, Volkmar Dierolf, Yasufumi Fujiwara, Masayoshi Tonouchi
Enhanced Luminescence Efficiency In Eu-Doped Gan Superlattice Structures Revealed By Terahertz Emission Spectroscopy, Fumikazu Murakami, Atsushi Takeo, Brandon Mitchell, Volkmar Dierolf, Yasufumi Fujiwara, Masayoshi Tonouchi
Physics & Engineering Faculty Publications
Eu-doped Gallium nitride (GaN) is a promising candidate for GaN-based red light-emitting diodes, which are needed for future micro-display technologies. Introducing a superlattice structure comprised of alternating undoped and Eu-doped GaN layers has been observed to lead to an order-of-magnitude increase in output power; however, the underlying mechanism remains unknown. Here, we explore the optical and electrical properties of these superlattice structures utilizing terahertz emission spectroscopy. We find that ~0.1% Eu doping reduces the bandgap of GaN by ~40 meV and increases the index of refraction by ~20%, which would result in potential barriers and carrier confinement within a superlattice …
Enhancement Of Er Luminescence From Bridge-Type Photonic Crystal Nanocavities With Er, O-Co-Doped Gaas, Zhidong Fang, Jun Tatebayashi, Ryohei Homi, Masayuki Ogawa, Hirotake Kajii, Masahiko Kondow, Kyoko Kitamura, Brandon Mitchell, Shuhei Ichikawa, Yasufumi Fujiwara
Enhancement Of Er Luminescence From Bridge-Type Photonic Crystal Nanocavities With Er, O-Co-Doped Gaas, Zhidong Fang, Jun Tatebayashi, Ryohei Homi, Masayuki Ogawa, Hirotake Kajii, Masahiko Kondow, Kyoko Kitamura, Brandon Mitchell, Shuhei Ichikawa, Yasufumi Fujiwara
Physics & Engineering Faculty Publications
A bridge-type photonic crystal (PhC) nanocavity based on Er,O-codoped GaAs is employed to realize enhancement of Er luminescence. By adjusting the structural design and measurement temperature, the cavity mode's wavelength can be coupled to Er luminescence. The peak emission intensity from an Er-2O defect center was enhanced 7.3 times at 40 nW pump power and 77 K. The experimental Q-factor is estimated to be over 1.2 x 104, and the luminescence intensity shows superlinearity with excitation power, suggesting Er luminescence amplification. This result would pave the way towards the realization of highly efficient single-photon emitters based on rare-earth elements.