Light-emitting diodes with 17% external quantum efficiency at 622 Mb/s for high-bandwidth parallel short-distance optical interconnects

We report on nonresonant cavity light-emitting diodes (NRC-LED) with large quantum efficiencies and high speed. A maximum quantum efficiency of 31% is measured for a device with an active layer thickness of 120 nm, and 18.7% for a device having an active layer of 30 nm, Further, we report on optical rise and fall times of NRC-LED's. Even when switched to current levels below 4 mA, at which the external quantum efficiency exceeds 17%, our NRC-LED'S have 10%-90% rise and fall times of less than 2 ns, As a result, eye diagrams taken at this current level at 622 Mb/s are wide open. This demonstrates the suitability of high-efficiency NRC-LED's for optical interconnects, Finally, from a system's viewpoint it is important to note that the optical output power of NRC-LED's decreases by only 0.36%/degrees C.