(100)-oriented gallium oxide substrate for ultra-violet emission by metalorganic vapor phase epitaxy
In this work we demonstrated the growth of high-quality GaN epilayers and InGaN/GaN multiple quantum wells (MQWs) with a 400 nm emission on (100) β-Ga2O3 substrate. The dislocation density of GaN epilayers may be obviously reduced by pulsed-growth, attributing to the enhanced three-dimension to two-dimension transformation process. The three-stage growth model had been proposed to clarify the underlying mechanism. Furthermore, pulsed-flow growth also enabled the relatively low-stress state (0.12 GPa) of GaN on (100) β-Ga2O3. Due to decreased quantum confined stark effect (QCSE), the MQWs on pulsed-GaN exhibited a lower blue-shift with increased excitation power densities and showed an increased combination rate. Additionally, the tendency for GaN separation was also observed, beneficial to heat dissipation of devices on (100) β-Ga2O3. This work may provide a prospective way to fabricate high-performance vertical structure ultra-violet light emitting diodes (LEDs) on (100) β-Ga2O3 substrate.