Electroluminescence from light-emitting device with erbium-doped TiO2 film sputtered onp+-Si substrate: Enhancement effect of codoping zirconium

Controllable Design of Minority Carrier Diffusion in npn Devices for Enhancing Er3+-Related Electroluminescence

“…EL peaks at 525, 550, 660, and 1540 nm in the spectra stem from the Er 3+ ion-related transitions, corresponding to the transitions of 2 H 11/2 to 4 I 15/2 , 4 S 3/2 to 4 I 15/2 , 4 F 9/2 to 4 I 15/2 , and 4 I 13/2 to 4 I 15/2 , respectively. It should be noted that in the visible EL spectra, there are no EL peaks resulting from the oxygen vacancy, which is regarded as the recombination center in oxide semiconductors and can be used as a sensitizer to transfer energy, inducing the absorption of photons by Er 3+ ions to generate radiative transition related to Er 3+ ions. − It is almost certain that the excitation mechanism of Er 3+ ions in npn heterojunction devices is a thermionic collision. The inset in Figure a is a photograph of device # npn 0.065 at the operating voltage of 9 V. A uniform and bright green luminescence can be observed throughout the entire ITO electrode, indicating that Er 3+ ions are well-distributed in the active layer, which is consistent with the results in Figure c,d.…”