Lead Performer: Sandia National Laboratory – Albuquerque, NM
Partner: Ohio State University – Columbus, OH
FY20 DOE Funding: $500,000
Project Term: October 1, 2018 – September 30, 2020
Funding Type: Lab Award

PROJECT OBJECTIVE

This project will use gallium nitride (GaN)-based multiple-junction light emitting diodes (MJ-LEDs) to develop a light source that can achieve both high output power and high wall plug efficiency (WPE). To reach this goal, the team will demonstrate that MJ-LEDs using interband tunnel junctions (TJs) to cascade multiple active regions can be achieved through voltage scaling rather than through current scaling. The researchers will demonstrate 450-nm TJ-LEDs with one, two, and three LED active regions. The external quantum efficiency (EQE) and optical output power will scale with the number of LED active regions, and the WPE will remain approximately constant.

PROJECT IMPACT

Since the power output of an MJ-LED is much higher than that of standard LEDs, the power density is also proportionately higher. The output power of an MJ-LED relative to a standard LED is multiplied by the number of active regions (N), so the power density of an MJ-LED is also N times higher than that of a comparable standard LED. Therefore, a MJ-LED with N = 3 (3x-MJ-LED) achieves the same WPE at an equivalent current density of 100 A/cm² as does a standard LED at 35 A/cm². If the project is successful, it could result in a droop-free LED that increases output power without reducing the power conversion efficiency microscopy methods.

CONTACTS

DOE Technology Manager: Brian Walker, brian.walker@ee.doe.gov
Lead Performer: Andrew Armstrong, Sandia National Laboratory