InGaN-based resonant-cavity light-emitting diodes with dielectric-distributed Bragg reflectors

Abstract

An InGaN-based resonant-cavity light-emitting diode (RC-LED) chip with a large chip area of 1 × 1 mm2 was fabricated using ZrO2/SiO2 dielectric-distributed Bragg reflectors (DBRs) on both sides of the cavity. After the growth of InGaN-based n- and p-epitaxial layers on a sapphire substrate, ZrO2/SiO2 layers for one DBR were deposited on it; then, holes with ∼10-µm diameters were patterned through the DBR layers. The DBR layer’s side of the whole sample was thermally bonded to a silicon substrate by using Au bonding metal; then, the sapphire substrate of the sample was removed using a laser lift-off technique. ZrO2/SiO2 layers for the other DBR were deposited on n-GaN for complete formation of the cavity. Through the electrical and the optical characterizations, we showed that our RC-LED has the improved optical output power and forward directionality in comparison with a conventional LED.