Electroluminescence from Er and Yb co-doped silicon dioxide layers: The excitation mechanism

Abstract

The excitation mechanism of photo- (PL) and electroluminescence (EL) of erbium ions co-implanted with ytterbium into the SiO 2 layer of light emitting MOS devices (MOSLED) was investigated. Ytterbium implanted and annealed samples exhibit the blue and near infrared electroluminescence. The blue electroluminescence at 470 nm appears due to cooperative up-conversion emission in the Yb 3+–Yb 3+ system, and the near infrared EL at 975 and 1025 nm corresponds to transitions from the multiple state 2F 5/2 to the 2F 7/2 ground state in the Yb 3+ ions. The Er implanted SiO 2 exhibits the luminescence in the blue-green and infrared region. The green and blue peaks correspond to radiative transitions from the 2H 11/2 or 4S 3/2 energy levels and from the 2H 9/2 or 4F 5/2 energy levels to the 4I 15/2 ground state, respectively. We have found that the energy transfer from Yb 3+ to Er 3+ ions exists only during photoluminescence excitation. The electroluminescence investigation shows the cooperative up-conversion in the Er 3+–Yb 3+ system.