Energy Transfer Under Electrical Excitation and Enhanced Electroluminescence in the Nanolaminate Yb,Er Co-Doped Al2O3 Films

The energy transfer from Yb3+ to Er3+ ions under electrical excitation which enhances the Er-related 1531 nm electroluminescence is evidenced, within the nanolaminate Yb,Er co-doped Al2O3 films fabricated by atomic layer deposition. The light-emitting devices based on these nanolaminates present an external quantum efficiency up to 24% and the power efficiency of 2.8x10(-3), approximate to 60% higher than the solely Er-doped Al2O3 device. The decay dynamics also support, with the radiative lifetime of the Yb3+ emission reduced while that of Er3+ emission rises. The Er3+ and Yb3+ ions are impact-excited by hot electrons, which stem from Poole-Frenkel conduction mechanism in Al2O3 matrix. This work certifies the potential of sensitizing Er3+ ions by the adjacent Yb3+ ions under electrical excitation, and applications of the rare earth-doped nanolaminates in silicon-based optoelectronics.