Violet semipolar (20-2-1) InGaN microcavity light-emitting diode with a 200 nm ultra-short cavity length

Abstract

Violet semipolar (20-2-1) InGaN microcavity light-emitting diodes (MC-LED) with a 200 nm ultra-short cavity length were demonstrated. The emission wavelength was 419 nm with a spectrum width of 20 nm. The external quantum efficiency (EQE) of MC-LED was constant at 0.8% for a forward current from 0.5 to 2 mA with the emitting area of 30×30 µm2. With increasing forward current, the peak wavelength and spectrum width of the emission showed almost no changes. For epitaxial growth, metal-organic chemical vapor deposition (MOCVD) was used. Substrate removal and tunnel-junction with an Ag-based electrode made possible the fabrication of the ultra-short 200 nm thick cavity MC-LED. This is more than a factor of 2 improvement compared to previous MC-LEDs of 450 nm cavity thickness sustaining 5 modes.

Exploration of Nontoxic Cs3CeBr6 for Violet Light-Emitting Diodes

“…Generally, fabricating LEDs have been developed by several different methods. The solution method includes spin-coating, − inkjet printing, , and blade-coating, and the vacuum method includes metal–organic chemical vapor deposition (MOCVD) and thermal evaporation . However, because of the low solubility of CsBr in organic solvents for the solution method, the rapid solvent evaporation may lead to nonuniform morphologies not ideal for LEDs.…”

Blue semipolar InGaN microcavity light-emitting diode with varying cavity lengths from 113 to 290 nm

“…We demonstrated ultra-short cavity MC-LED with a geometrical cavity length of 200 nm which had a peak external quantum efficiency (EQE) of 0.8%. 3) Recently, by removing the dry etching damage of the sidewall [11][12][13] using phosphoric acid (H 3 PO 4 ) treatment, 14) we could increase the peak EQE up to 7.3%, 15) which is almost the same as that of a conventional c-plane μLED. The demonstration of MC-LEDs with a high EQE of 7.3% and a single mode emission should pave the way for the application of display and others.…”

“…These MC-LEDs have advantages of thermal stability and spectral purity since the spectral width and shape are determined by the overlap of the InGaN quantum well (QW) emission and the cavity mode. 3) In addition, the emission of MC-LEDs is more directional than conventional LEDs. [4][5][6][7][8][9][10] These advantages suggest MC-LEDs could be the best fit for display applications.…”

“…9) Nobody has studied the short cavity of less than 450 nm 16) except for our previous results with a geometrical cavity length of 200 nm. 3) Here we studied the shortest cavity length of 113 nm, which could have the highest LEE of 35%.…”

630-nm red InGaN micro-light-emitting diodes (<20 μm × 20 μm) exceeding 1 mW/mm2 for full-color micro-displays

“…In this study, we attributed this behavior to two possible reasons. First, the relatively large leakage current in Figure 2a might lead to weak emission intensity and low EQE of the µLEDs at low current densities [39]. The second dominant reason was the high non- The on-wafer EQE reached 0.18% at a peak wavelength of 630 nm at 50 A/cm 2 .…”