Polarization-Enhanced Tunnel Junction Using A Double Heterojunction Between A Wurtzite Material And A Rocksalt Material
Tech ID: 31758 / UC Case 2020-082-0
Existing tunnel junctions are based on wurtzite materials, and use either GaN or lnGaN as the tunnel layer. The polar crystal structure of GaN affords the opportunity to combine it with a non-polar structure to create a large polarization charge at the interface of these two materials. This leads to higher and more favorable tunnel currents. InGaN is commonly used as the non-polar material, but other materials can offer further performance advantages.
Researchers at the University of California, Santa Barbara have developed a ScN tunnel layer which allows for much larger electric fields (an order of magnitude larger) and offers easier implementation in GaN devices. The high electric fields realized by this material translates to a thinner tunnel layer that is less absorbing of the emitted light. ScN is also easier to grow on GaN due to a much smaller lattice mismatch compared to lnGaN. The small, indirect band gap of ScN enables higher tunneling currents and further reduces the reabsorption of light.
- Less light reabsorption
- More energy efficient
- Higher tunneling current
- Easier implementation on GaN
- GaN devices
- Laser diodes