Improving optoelectronic performance and modulation bandwidth of green µ-LEDs via a compound pre-strained strategy

A composite strain-modulation strategy to achieve high-performing green µ-LED devices for visible light communication is proposed. Compared with the conventional pre-well structure, introducing a pre-layer to enlarge the lateral lattice constant of the underlayer decreased the strain in the overall strain-modulated layer and MQW. This improved the crystal quality and suppressed the quantum confinement Stark effect. Using this modulation strategy, the green µ-LED array with the compound pre-strained structure exhibited a light output power of 20.5 mW and modulation bandwidth of 366 MHz, corresponding to improvements of 61% and 78%, respectively, compared with those of µ-LEDs with a pre-well structure.