All‐Solution Processed Multicolor Patterning Technique of Perovskite Nanocrystal for Color Pixel Array and Flexible Optoelectronic Devices

Abstract

In the present study, a new patterning method is introduced through the surface modification and stabilization of perovskite nanocrystals, which is compatible with conventional photolithography process based on all‐solution processes. Chemically designed gel‐type silica‐coated CsPbX3 (X = Br, I, etc.) perovskite nanocrystals combined with dip coating method are introduced to form stable and uniform films. Analyses of the physical and chemical states of nanocrystals and investigation of the kinetics in silica formation are conducted. In an optimized condition, physically uniform and chemically stable perovskite thin films are deposited on various substrates such as flexible, stretchable substrates, or even nonflat objects. By adopting these advantages and developing stable photolithographic chemicals, the high resolution patterns are successfully patterned with green and red emitting CsPbBr3 and CsPbBr3I3−x perovskites with the size down to 5 µm of radius and even a multicolor pixel array which can be used for the color filter, light converting or detecting applications. Flexible white light emitting diode is also fabricated with a large color gamut coverage. This work provides a fundamental understanding of perovskite nanocrystals, and also offers a technological breakthrough enabling various optoelectronic applications.

Multifunctional Daytime Radiative Cooling Devices with Simultaneous Light-Emitting and Radiative Cooling Functional Layers

“…The silica coating process was conducted to shield the perovskite from the destructive effects of PDMS during incorporation and enhance the cooling property of the device (as will be discussed later). The silica-coated CsPbX 3 NC solution was synthesized using the 3-aminopropyltriethoxysilane (APTES) treatment method (Figure c). , APTES was injected during synthesis to maintain the high PLQY and colloidal stability by coordinating the amino group of APTES with the surface of the NCs. The sequential hydrolysis process facilitates reactions between amino groups attached to the NCs and water molecules, forming silica shells on perovskite NCs.…”

Mn-Doped Organic–Inorganic Perovskite Nanocrystals for a Flexible Luminescent Solar Concentrator

“…Apart from bulk halide perovskites that serve as light absorbers for perovskite solar cells, − perovskite nanocrystals (PeNCs) are materials of interest as emitter centers for lighting applications. − PeNCs of varied compositions that have been synthesized with diverse methods exhibit varied optical properties, crystallinity, and chemical stability. , Various synthetic methods such as ligand-assisted reprecipitation (LARP), top-down , and hot-injection methods have been developed for the synthesis of PeNCs. The LARP method utilizes polar solvents, the residues of which lead to rapid degradation of PeNCs; , these synthesized PeNCs have poor crystallinity and stability, but researchers subsequently developed modified LARP techniques to stabilize PeNCs. , The top-down method is an easy way to synthesize PeNCs, but a large distribution of size of PeNCs and a prolonged reaction are drawbacks of this method.…”

Direct Optical Lithography of CsPbX3 Nanocrystals via Photoinduced Ligand Cleavage with Postpatterning Chemical Modification and Electronic Coupling

“…Unfortunately, the ionic nature of LHP NCs typically makes them incompatible with traditional photolithography workflows that use polar solvents. To overcome this issue, modifications to either the NCs or the photolithography process have been explored such as using silica-encapsulated LHP NCs, 8 using an orthogonal fluorinated photoresist and developer, 24 and adding a self-healing recrystallization step. 9 Alternatively, LHP NCs can be photopatterned directly by including a photosensitive component into the LHP NC solution (or LHP NC precursor solution).…”

“…Colloidal lead halide perovskite (LHP) nanocrystals (NCs) have been intensely investigated due to their facile solution-phase syntheses, defect tolerance, and fascinating optoelectronic properties. − LHP NCs have been researched for use in light-emitting diodes (LEDs), − color conversion filters, lasers, − solar cells, , visible-light photodetectors, X-ray scintillators, , and quantum emitters . As the library of LHP NCs and perovskite-related nanomaterials continues to expand toward increased complexity, there is a need to develop methods for integrating LHP NCs in practical devices.…”