Healthy and stable lighting via single-component white perovskite nanoplates

Two-dimensional Cs3Sb2Br9 inducing transformation of three-dimensional CsPbBr3 to nanoplates

This communication describes an effective morphological control strategy involving introducing two-dimensional (2D) Cs3Sb2Br9 to induce a transformation of three-dimensional (3D) CsPbBr3 to 2D nanoplates (NPLs). By tuning the Sb/Pb ratio, 2D CsPbBr3 NPLs exhibiting a deep-blue emission centered at a wavelength of 464 nm with an FWHM of 24 nm have been produced. The absence of organic ligands in these high-quality 2D NPLs mitigate the instability issue induced by organic ligand migration and penetration, and these NPLs exhibit 80% of the initial PL intensity after 55 days.

Enhanced stability of CsPbBr3 nanocrystals through Al2O3 and polymer coating

Lead halide perovskite nanocrystals have emerged as a promising candidate for next-generation display applications due to their attractive optical properties and low-cost production. However, the environmental stability of perovskite remains a major challenge, hindering their practical applications and scalability for commercialization. In this study, we present an effective method to enhance the stability of CsPbBr3 nanocrystals by coating them with a combination of Al2O3 and a polymer. The unique double protection structure significantly improves their resistance to moisture, heat, and polar solvents. It is worth noting that compared with the ordinary CsPbBr3 nanocrystals, the modified nanocrystals have better stability and higher luminous intensity. After soaking in water for 360 hours, the modified nanocrystals retained 85% of their initial luminous intensity. Under optimal conditions, the luminous intensity of modified nanocrystals increased by 36%. Furthermore, the thermal stability and organic solvent resistance of the nanocrystals are improved compared with the nanocrystals uncoated with Al2O3. The synthesized white light emitting diode using the modified PNCs achieves a color gamut coverage rate of 129% under standard NTSC, and 95% under standard Rec.2020, indicating its potential for future display applications. This research presents a promising approach for the development of stable perovskite nanocrystals with enhanced performance in various optoelectronic devices.

Full-color micro-LED display with photo-patternable and highly ambient-stable perovskite quantum dot/siloxane composite as color conversion layers

In this paper, we successfully fabricated color conversion layers (CCLs) for full-color-mico-LED display using a perovskite quantum dot (PQD)/siloxane composite by ligand exchanged PQD with silane composite followed by surface activation by an addition of halide-anion containing salt. Due to this surface activation, it was possible to construct the PQD surface with a silane ligand using a non-polar organic solvent that does not damage the PQD. As a result, the ligand-exchanged PQD with a silane compound exhibited high dispersibility in the siloxane matrix and excellent atmospheric stability due to sol-gel condensation. Based on highly ambient stable PQD/siloxane composite based CCLs, full-color micro-LED display has a 1 mm pixel pitch, about 25.4 pixels per inch (PPI) resolution was achieved. In addition, due to the thin thickness of the black matrix to prevent blue light interference, the possibility of a flexible display that can be operated without damage even with a bending radius of 5 mm was demonstrated.