Infrared LEDs and microcavities based on erbium-doped silicon nanocomposites

We demonstrate stable room-temperature electroluminescence at 1.54 μm under both forward and reverse bias conditions from erbium-doped silicon nanocomposites. We also show enhanced and tunable emission from erbium when incorporated in porous silicon based microcavities. Erbium is infiltrated in the pores by cathodic electrochemical migration of the ions followed by high temperature annealing (600–1100°C) to produce a composite material made of silicon nanocrystals and silicon dioxide. The devices exhibit an exponential electroluminescence dependence in both bias conditions as a function of the driving current and driving voltage. In reverse bias, the external quantum efficiency reaches 0.01%. The devices show a large temperature dependence of the electroluminescence intensity. The electroluminescence intensity decreases by a factor of 24 in reverse bias and 2.6 in forward bias when the temperature increases from 240 to 300 K. The photoluminescence from the erbium-doped microcavity resonators is enhanced by more than one order of magnitude and tuned to emit in areas where the natural erbium emission is very weak.