High Efficiency UltraViolet Light Emitting Diodes
TS-015164 — New UV LED designs that use quantum mechanical tunneling, to inject holes or electrons, can greatly enhance the efficiency and power of these devices.
Efficient and compact ultraviolet light sources could address a wide range of societal needs in the areas of water purification, air disinfection, and sensing. Ultraviolet light emitting diodes (UV LEDs) are more compact and environmental friendly than conventional UV lamps, and have the potential…
Efficient and compact ultraviolet light sources could address a wide range of societal needs in the areas of water purification, air disinfection, and sensing. Ultraviolet light emitting diodes (UV LEDs) are more compact and environmental friendly than conventional UV lamps, and have the potential to replace conventional gas-based UV lamps in current applications as well as enable new applications. Tunneling current injected UV LEDs provides an elegant approach to break the limitations, and they are predicted to enable highly efficient UV emitters. This creates a huge market opportunity for a tunneling injected UV light emitters.
Researchers at the Ohio State University, led by Dr. Siddharth Rajan, have developed new designs for UV LEDs that use quantum mechanical tunneling. The tunnel junction design for III-Nitride UV LEDs has the potential to dramatically increase the External Quantum and Wall Plug (EQE, WPE) efficiency, and output power. To solve both the low EQE and WPE problem, a tunnel junction based UV LED design using a AlGaN/InGaN/AlGaN tunnel junction (TJ) as a tunneling junction to p-AlGaN was developed. The tunnel junction takes advantage of non-equilibrium hole injection through tunneling, which is not limited by the thermal activation energy of acceptors.
- Water purification
- Medical or biological analysis
- Reduction of both absorption and electrical losses, leading to higher external quantum and wall plug efficiency
- Increased output power
- Potential to be 40% efficient versus 4% of current standard UV LEDs (Wall Plug Efficiency)
- Tunnel Junction structure projects to lower cost per Watt UV LEDs
- Light extraction from top side to potentially eliminate Flip Chip bonding
- Increase the injection efficiency especially for deep UV LEDs
- Enables n-type top contact instead of p-type contact, which reduces contact resistance and voltage drop across the contact