Energy transfer from Gd to Er atoms in SiO2(GdEr)-MOSLEDs produced by ion implantation

The excitation mechanism of electroluminescence (EL) of erbium ions co-implanted with gadolinium into the SiO2 layer of light emitting MOS devices (MOSLED) was investigated. Er ions were implanted into the SiO2 layer with a concentration of 2%, subsequently implanted by gadolinium ions with concentrations of 0.5, 1.5 and 3%. The Er implanted SiO2 exhibits the typical peak at 1540 nm and weak luminescence in the green and blue region. Two green peaks correspond to the radiative transitions from the 2H11/2 and 4S3/2 energy levels to the 4I15/2 ground state and blue peaks to those from the 2H9/2 and 4F5/2 to the 4I15/2. Silicon dioxide containing erbium co-implanted with Gd exhibits two different excitation mechanisms: direct Er3+ ion excitation by the hot electrons and the energy transfer from the 6PJ energy level of Gd to the 4f energy states of Er3+ leading to an increase of the EL of Er in the visible region. The additional implantation of Gd has no influence on the infrared luminescence at 1540 nm.