Fig. 1. (a) Epitaxial wafer; (b) three subpixels of a green μLED, a blue NR-μLED, and a red QD-NR-μLED; (c) deposition of TCO film and pn electrodes; (d) covering DBR filter; (e) full-color display panel composed of the proposed hybrid QD-NR-μLEDs; (f) cross-sectional view of a single RGB pixel.

Fig. 2. (a) PL emission spectra of NR-μLEDs with and without ALD passivation; (b) TD-TRPL curves of NR-μLEDs with and without ALD passivation at 15 K and 300 K, respectively.

Fig. 3. (a) FLOM image of patterns printed by red QDs on a glass by using the latest SIJ printing system (the inset depicts minimum linewidth); (b) AFM image of deposited QDs.

Fig. 4. Absorption curve of red QDs and electroluminescence (EL) spectrum of blue NR-μLEDs (inset depicts a schematic configuration of spraying red QDs on blue NR-μLEDs using the SIJ printing system).

Fig. 5. (a) SEM image of RGB pixel array (top view); (b) SEM image of NR-μLED with 30° tilt angle; (c) TEM image of the contact area between MQWs and QDs; (d) TEM image of 1 nm Al2O3 deposited on the sidewall of an NR-μLED through ALD.

Fig. 6. (a) Without ALD passivation, TRPL curves of NR-μLEDs with and without red QDs; (b) with 1-nm ALD passivation, TRPL curves of NR-μLEDs with and without red QDs.

Fig. 7. Reflectance spectrum of the DBR.

Fig. 8. (a) EL spectra of RGB hybrid QD-NR-μLEDs; (b) color gamut of RGB hybrid QD-NR-μLEDs, NTSC, and Rec. 2020.