Quantum Dots, Photonic Crystal Form LED

Scientists at the University of Michigan in Ann Arbor have reported an electrically driven LED comprising InAs/GaAs quantum dots in a GaAs photonic crystal structure. They described the fabrication and operation of the 1.04-µm emitter in the Nov. 11 issue of Applied Physics Letters.

The device, grown by molecular beam epitaxy, features a triangular-lattice photonic crystal of 300-nm-diameter airholes at a lattice constant of 420 nm and 20 x 6-nm quantum dots. Thermal annealing of the structure at 740 °C shifted the emission peak to the desired wavelength, boosted intensity and narrowed the emission linewidth.