Red InGaN micro-light-emitting diodes (>620 nm) with a peak external quantum efficiency of 4.5% using an epitaxial tunnel junction contact

Abstract

We present efficient red InGaN 60 × 60 μm2 micro-light-emitting diodes ( μLEDs) with an epitaxial tunnel junction (TJ) contact. The TJ was grown by metal-organic chemical vapor deposition using selective area growth. The red TJ μLEDs show a uniform electroluminescence. At a low current density of 1 A/cm2, the emission peak wavelength is 623 nm with a full-width half maximum of 47 nm. The peak external quantum efficiency (EQE) measured in an integrating sphere is as high as 4.5%. These results suggest a significant progress in exploring high efficiency InGaN red μLEDs using TJ technology.

Demonstration of 621-nm-wavelength InGaN-based single-quantum-well LEDs with an external quantum efficiency of 4.3% at 10.1 A/cm2

“…4(b). 16,18,20,21,23,26,33,[37][38][39][40][41] We also calculated the EQEs and WPEs of the LEDs at various injection currents, as shown in Fig. 5.…”

Significant Quantum Efficiency Enhancement of InGaN Red Micro-Light-Emitting Diodes with a Peak External Quantum Efficiency of up to 6%

“…It is noted that the peak EQE of 6% is the highest one reported among the InGaN-based red μLEDs. 17,[19][20][21][22][23][24][25][26]29,30 The EQE of the InGaN μLEDs maintains as high as 4.5% at 100 A/cm 2 .…”

Progress of InGaN-Based Red Micro-Light Emitting Diodes

“…Fewer damage sidewalls etching process is a good approach to improve the efficiency of ultra-small InGaN red µLEDs. More recently, Li et al from UCSB reported 623 nm red InGaN µLEDs (60 × 60 µm 2 ) with a peak EQE of 4.5% using epitaxial tunnel junction (TJ) contact [27]. GaN TJ offers a better current spreading and less optical loss, which can improve efficiency.…”