Reactivation of damaged rare earth luminescence centers in ion-implanted Metal-Oxide-Silicon light emitting devices

Charge trapping and quenching of the electroluminescence (EL) in SiO2 layers implanted by Ge and rare earth (RE) ions during hot electron injection were investigated. In case of the SiO2:Ge layer the EL quenching is caused by the transformation of the luminescent defects (≡Ge-Si≡ or ≡Ge-Ge≡) to optically not active centers during hot electron excitation, whereas the EL from rare earth centers is quenched due to the electron trapping by RE-centers or their surrounding but not due to their optical deactivation. Therefore, the flash lamp post-injection annealing releasing trapped electrons reactivates RE centers and increases the operating time of Metal-Oxide-Silicon light emitting devices (MOSLEDs).