1.5 μm electroluminescence from organic light emitting diodes integrated on silicon substrates

We have produced a silicon based organic light emitting diode (OLED) which emits 1.5 μm electroluminescence at room temperature. The emitting layer used was erbium tris(8-hydroxyquinoline) and energy is transferred from excitons formed on the organic ligands into the erbium ion. Characteristic emission is observed through the silicon substrate at 1.5 μm due to the ⁴I_13/2 to ⁴I_15/2 intra-atomic transition. Whilst the device is not suited to conventional OLED applications, due to the long lifetime of the ⁴I_13/2 to ⁴I_15/2 transition, it is a significant step towards the development of a 1.5 μm laser which can be integrated onto a silicon waveguide.