[14a-A303-1~7] 13.8 Optical properties and light-emitting devices

▲ [14a-A303-2] Ultrafast carrier dynamics and excitation efficiency of Eu³⁺ ions in GaN:Eu

〇Dolf Timmerman¹, Masaaki Ashida¹, Shuhei Ichikawa¹, Jun Tatebayashi¹, Yasufumi Fujiwara¹ (1.Osaka University)

Keywords:Quantum efficiency, Carrier dynamics, GaN

We present a comprehensive study on the ultrafast carrier dynamics, energy transfer mechanism from the GaN-host to Eu ions, and luminescence quantum efficiency (QE) in GaN:Eu. The room temperature QE is strongly dependent on the excitation conditions and can reach nearly 30%. The timescales involved in the carrier trapping and energy transfer have been determined by probing the ultrafast carrier dynamics, as well as the initial dynamics of the Eu-related luminescence. Emission from Eu was observed within the experimental resolution of 100 ps after a pulsed excitation of the GaN host. Our results indicate that the energy transfer in GaN:Eu takes place on very short timescales and underpins the observed high quantum efficiency. The benefits of the short free-carrier lifetime in GaN:Eu for micro-LED applications will be discussed.