Low-temperature printable carbon based planar-heterojunction perovskite solar cells with efficiencies exceeding 15% were demonstrated by using a TiO2/SnO2bilayer as ETL together with CuPc as HTL.

All inorganic cesium lead halide (CsPbX3, X = Cl, Br, I) perovskite nanocrystals (PNCs) exhibit promising applications in light-emitting devices due to their excellent photophysical properties. Herein, we developed a low-cost and convenient method for the preparation of CsPbX3 PNCs in a multiligand-assisted reaction system where peanut oil is applied as a ligand source. The mixed-halide PNCs with tunable optical-band gap were prepared by mixing the single-halide perovskite solutions at room temperature. The resulting PNCs had good monodispersity, with dimensions of 8–10 nm, high photoluminescence quantum yield (96.9%), narrow emission widths (15–34 nm), and tunable emission wavelength (408–694 nm), covering the entire visible spectrum. Additionally, various morphologies of PNCs, such as nanospheres, nanocubes, and nanowires, were obtained by controlling reaction temperature and time, and the amount of oleamine with multiple ligands in peanut oil potentially playing a dominant role in the nucleation/growth processes of our PNCs. Finally, the resulting CsPbBr3 PNCs were employed to develop a white light-emitting diode (WLED), demonstrating the potential lighting applications for our method.

We report that ethanol, used together with water, plays a crucial role in tuning the structures of a zirconium-based metal–organic framework and the 12-connected MOF-801, as well as the possible mechanisms of this modulating effect. By employing a cosolvent system of ethanol and water at just under room temperature without the presence of a monotopic carboxylic acid as the modulator, MOF-801 in various morphologies of different sizes could be synthesized. A linear correlation between the ethanol/water ratio and the crystal sizes is also demonstrated. The growth mechanism is mainly explained by ethanol’s bonding with the metal ion clusters and the Marangoni flow effect. Ethanol competes with the linker molecules in coordinating with the Zr metal clusters, a role similar to that of the modulators. The Marangoni flow effect, which dominates at a certain solvent ratio, further promotes the 1D alignment of the MOF-801 crystals.

Herein, we develop a novel strategy for preparing all-inorganic cesium lead halide (CsPbX3, X= Cl, Br, I) perovskite nanocrystals (NCs)@Zn-based metal-organic framework (MOF) composites through interfacial synthesis. The successful embedding of fluorescent perovskite NCs in Zn-MOFs is due to the in-situ confined growth, which is attributed to the re-nucleation of water-triggered phase transformation from Cs4PbBr6 to CsPbBr3. The controllable synthesis of mixed-halide based composites with various emission wavelength can be achieved by adding the desired amount of halide (Cl or I) salts in the re-nucleation process. More importantly, the anion exchange reaction is inhibited among various composites with different halogen atoms by being trapped in MOFs. Besides, a white light-emitting diode (WLED) is produced using a blue LED chip with the green-emitting and red-emitting composites, which has a color coordinate of (0.3291, 0.3272) and a wide color gamut. This work provides a novel route to achieving perovskite NCs growth in MOFs, which also can be extended to the other NCs embedded in frames as well.

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