III-Nitride optoelectronics

We are investigating next-generation GaN and AlGaN-based optoelectronics using novel concepts such as interband tunnel junctions, multiple active region emitters, and polarization engineering. Current active projects are focused an achieving tunneling-based cascaded LEDs, and ultraviolet UV LEDs using AlGaN-based tunnel junctions.

Recent publications and presentations

Invited Presentation:

  • Advances in III-Nitride Materials & Photonic Devices (IIIN-MPD), 22nd January 2022. (slides)


  1. Zhang, Y., Krishnamoorthy, S., Johnson, J.M., Akyol, F., Allerman, A., Moseley, M.W., Armstrong, A., Hwang, J. and Rajan, S., 2015. Interband tunneling for hole injection in III-nitride ultraviolet emitters. Applied Physics Letters, 106(14), p.141103.
  2. Zhang, Y., Krishnamoorthy, S., Akyol, F., Allerman, A.A., Moseley, M.W., Armstrong, A.M. and Rajan, S., 2016. Design and demonstration of ultra-wide bandgap AlGaN tunnel junctions. Applied Physics Letters, 109(12), p.121102.
  3. Akyol, F., Krishnamoorthy, S., Zhang, Y. and Rajan, S., 2015. GaN-based three-junction cascaded light-emitting diode with low-resistance InGaN tunnel junctions. Applied Physics Express, 8(8), p.082103.
  4. Krishnamoorthy, S., Nath, D.N., Akyol, F., Park, P.S., Esposto, M. and Rajan, S., 2010. Polarization-engineered GaN/InGaN/GaN tunnel diodes. Applied Physics Letters, 97(20), p.203502.