III-nitride tunnel junctions for efficient solid state lighting

Krishnamoorthy S., Akyol F., Rajan S.

Conference on Gallium Nitride Materials and Devices IX, San-Francisco, Costa Rica, 3 - 06 February 2014, vol.8986 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 8986
  • Doi Number: 10.1117/12.2039382
  • City: San-Francisco
  • Country: Costa Rica
  • Yıldız Technical University Affiliated: No

Abstract

We discuss the design and demonstration ultra-low resistance III-nitride tunnel junctions, and how tunnel junctions could solve the long-standing problem of efficiency droop in solid state lighting. We have used nanoscale band engineering based on polarization and mid-gap states to reduce tunneling resistance by four orders of magnitude. We will discuss experimental demonstration of highly efficient tunnel junctions (resistivity similar to 0.1 mOhm-cm(2)) in PN junctions, p-contact free LEDs, and multiple junction structures. Finally we will show how tunneling based carrier regeneration in multiple active region cascade LEDs could help to enable low current, high voltage operation to overcome the efficiency droop problem.