Figure 1

Model of the trap assisted excitation of Eu⁺³ ion in GaN:Eu QW active region. (a) The confined electron-hole in the GaN:Eu QW are captured by the traps (purple arrows) which are close to the vicinity of Eu⁺³ ion and results in (b) complex formation. (c) After the complex formation the electron-hole pair can recombine at the trap level by releasing a non-radiative energy to the crystal lattice (brown arrow) or release a non-radiative energy used for the excitation of the nearby Eu⁺³ ion (energy transfer process-gold arrow) or it can dissociate by releasing the electron-hole back to the GaN:Eu QW. Similarly, the excited Eu⁺³ can recombine non-radiatively by releasing energy to the crystal lattice (brown arrow) or release non-radiative energy for complex formation (energy back-transfer process, dark blue arrow) or recombine radiatively with photon emission (red arrow).