Enhanced Hole Injection by P-Type Active Region and Lateral Injection in InAlGaN LEDs
Tech ID: 31875 / UC Case 2020-068-0
Conventional LEDs for solid-state lighting are plagued by current droop. Current droop can, in principle, be addressed by stacking multiple quantum wells (MQWs) to reduce carrier density, but poor hole injection in the MQWs poses another barrier to device performance as a result of increased material volume.
Researchers at the University of California, Santa Barbara have created an LED device where the MQW active region is fully or partially p-type doped and the active quantum wells (QWs) are located on the p-side of the junction, which eliminates the issue of poor hole injection that is observed in conventional LEDs. Advantages of this technology include low-droop in GaN-based LEDs by volumetric hole injection, more design freedom for thick active regions with large number of QWs for high efficiency, improved efficiency of green LEDs, and mitigation of the size-dependent efficiency drop in microLEDs. By eliminating the need for hole transport in such structures, the transport delays between the wells are removed, which significantly improves the modulation bandwidth of the LEDs – an essential feature for visible-light communications.
- Increases device efficiency
- Decreases carrier density
- Decreases thermal droop
- Enables volumetric hole injection
- Applicable to all LEDs and lasers
- Monolithically integrates white LEDs
- Visible Light Communication