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

Abstract

We demonstrate a significant quantum efficiency enhancement of InGaN red micro-light-emitting diodes (μLEDs). The peak external quantum efficiency (EQE) of the packaged 80 × 80 μm2 InGaN red μLEDs was largely increased to 6.0% at 12 A/cm2, representing the significant process in exploring the efficiency of InGaN red μLEDs. The improvement of the EQE is attributed to the significant enhancement of the quantum efficiency, which is confirmed by the electron–hole wavefunction overlap in the InGaN quantum well from the band gap simulation and the photoluminescence intensity ratio at room temperature/low temperature. Ultrasmall 5 × 5 μm2 InGaN red μLEDs were also obtained, which show a high peak EQE of 4.5%. This work demonstrates a simple approach to achieving highly efficient InGaN red μLEDs, which are very promising candidates for ultrasmall red μLEDs required by AR/VR displays.

Significant reduction in sidewall damage related external quantum efficiency (EQE) drop in red InGaN microLEDs (∼625 nm at 1 A cm−2) with device sizes down to 3 μm

“…Recently Panpan Li et al fabricated 80 μm × 80 μm and 5 μm × 5 μm red microLEDs. 38) A peak EQE of 6% was achieved for the 80 μm device, while the EQE still reduced to 4.5% for the 5 μm device, showing a reduction of efficiency for smaller devices.…”

Merging automatic differentiation and the adjoint method for photonic inverse design

“…In the example shown in figure 4, our primary objective is to enhance the far-field emission of a µLED (nanoscale light-emitting diode) within a specific solid angle, denoted as Γ, also known as LEE (light extraction efficiency). The field of µLED development is rapidly advancing, attracting substantial research interest and holding considerable industrial relevance [62][63][64][65]. The targeted optimization can be mathematically represented by the function max Ω LEE Γ = max Ω P Γ /P 0 = max Ω 1 P0…”

III-Nitride Materials: Properties, Growth, and Applications

“…[30,[37][38][39][40][41][42]. The EQE of InGaN red microLEDs has already reached 7.4%, demonstrating promise for application soon [43,44]. Blue and green InGaN lasers have also achieved inspiring performances [45,46].…”