Room temperature 1.6 μm electroluminescence from Ge light emitting diode on Si substrate

We report the room temperature electroluminescence (EL) at 1.6 μm of a Ge n+/p light emitting diode on a Si substrate. Unlike normal electrically pumped devices, this device shows a superlinear luminescence enhancement at high current. By comparing different n type doping concentrations, we observe that a higher concentration is required to achieve better efficiency of the device. Thermal enhancement effects observed in temperature dependent EL spectra show the capability of this device to operate at room temperature or above. These detailed studies show that Ge can be a good candidate for a Si compatible light emitting device.