Fig. 1. (a) 4-inch semipolar (20−21) blue LED epitaxial wafer and 2-inch commercially available c-plane InGaN/GaN LED wafer with its rear side polished; (b) SEM image showing a cross-sectional view of the semipolar LED epitaxial wafer; (c) optical microscopic image of the 30 μm μLED array sample; schematic diagrams of (d) the semipolar (20−21) μLED structures, (e) the fabrication process and a photo of the color conversion layer, and (f) proposed PNC–μLED device.

Fig. 2. XRD patterns of the CsPbBrI2−SiO2 and CsPbBr3−SiO2 PNCs.

Fig. 3. TEM images of (a) CsPbBr3−SiO2 and (c) CsPbBrI2-C PNCs; high-resolution TEM images of the (b) CsPbBr3−SiO2 and (d) CsPbBrI2−SiO2 PNCs; and size distributions of (e) CsPbBr3 and (f) CsPbBr2. Inset in (a) is the TEM image of MS before sintering.

Fig. 4. EDS element maps of (a) CsPbBrI2−SiO2 and (b) CsPbBr3−SiO2 PNCs.

Fig. 5. UV-vis absorption and PL spectra of (a) CsPbBrI2−SiO2 and (b) CsPbBr3−SiO2. The PL properties of the red and green PNCs, as well as the solution-processed samples, are shown in response to (c) ambient and (d) blue light exposure.

Fig. 6. (a) Current density–voltage (J–V) curve for the 30 μm μLED array and its illuminated image; (b) EL spectra for different injection currents; (c) peak wavelength shift and FWHM as a function of current density; and (d) EQE and emitted power as a function of current density.

Fig. 7. (a) Polarization characteristics of the 30  μm×4 semipolar μLED array; and (b) TRPL curves for the semipolar μLED array and the PNCs.

Fig. 8. (a) Schematic diagram for bandwidth measurement; (b) frequency response for the PNC–μLED; (c) schematic diagram for the eye diagram measurement; (d)–(f) eye diagrams of the PNC–μLED at 1.0, 1.2, and 1.5 Gb/s, respectively.

Fig. 9. (a) Color gamut of the PNC–μLED under different current densities; and (b) color shift of blue semipolar μLEDs under different current densities.