Strongly-ligated perovskite quantum dots with precisely controlled dimensions and architectures for white light-emitting diodes

a 3D framework. The A-site cations occupy the cavity within the framework. Metal halide perovskites have a relatively soft lattice and a dynamically disordered crystal structure which results in tunable charge-carrier recombination rates and other nonclassical semiconductor characteristics. [1] Metal halide perovskites have been extensively studied for solar energy conversion over the past decade due to their intriguing optoelectronic properties, including near-perfect crystalline structures, [2] tunable direct bandgaps, [3] large absorption coefficient (1.5 × 10 4 cm −1 at 550 nm), [4] high ambipolar mobility (≈20 cm 2 V −1 s −1 ), [5] long carrier diffusion lengths (100-1000 nm; ≈175 µm in MAPbI 3 single crystals) (L eff,e /L eff,h < 1), [6] small exciton binding energy (≈30 meV), [7] high defect tolerance, [8] solution processability, and low processing cost. [9] Notably, the certified power conversion efficiency (PCE) of single-junction perovskite solar cells has rapidly increased from 3.8% in 2009 to 25.2% in 2019. [10] It is also notable that charge carriers within metal halide perovskites can undergo radiative recombination to emit light, making them promising candidates as next-generation light sources for light-emitting diodes (LEDs) [11] and lasers. [12] Bulk perovskite, however, exhibits limited photoluminescence quantum yield (PLQY) due to the presence of mobile ionic defects and small exciton binding energy. [13] In contrast, perovskite nanocrystals (PNCs) possess strong quantum confinement and display improved optoelectronic properties from their bulk counterparts. [14] Notably, metal halide PNCs possess high luminescence, narrow full width at half maximum, and a composition-and size-dependent bandgap. [15] The photoluminescence (PL) of metal halide PNCs can be readily tuned from ultraviolet (UV) to near-infrared wavelengths by simply tailoring their composition or altering their size relative to their Bohr diameters.Hot-injection and ligand-assisted reprecipitation methods represent the two most-developed colloidal synthesis approaches of metal halide PNCs. [13,16] The use of organic capping ligands in synthesis enables nanoscale growth of metal halide perovskite crystals and actively passivates their surface defects, in a manner similar to that of conventional NC Metal halide perovskite nanocrystals (PNCs) have recently garnered tremendous research interest due to their unique optoelectronic properties and promising applications in photovoltaics and optoelectronics. Metal halide PNCs can be combined with polymers to create nanocomposites that carry an array of advantageous characteristics. The polymer matrix can bestow stability, stretchability, and solution-processability while the PNCs maintain their size-, shape-and composition-dependent optoelectronic properties. As such, these nanocomposites possess great promise for next-generation displays, lighting, sensing, biomedical technologies, and energy conversion. The recent advances in metal halide PNC/polymer nanocomposites are summarized here. F...

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“…Star-like poly(acrylic acid)-block-polystyrene PAA-b-PS CsPbBr 3 91.4% [17a] 71% [82] [17a,82] 67% [82] [82]…”

Section: Sebs Cspbbr 3 N/a [29]mentioning

confidence: 99%

“…[83] Hollow PNCs with PS chains covalently tethered to their surface were crafted by tailoring the composition of multiarm star-shaped triblock copolymer from P4VP-b-PAA-b-PS to PS-b-PAA-b-PS. [82]…”

Section: In Situ Synthesis Of Pncs In the Presence Of Polymer Nanoreactorsmentioning

confidence: 99%

Recent Advances in Synthesis, Properties, and Applications of Metal Halide Perovskite Nanocrystals/Polymer Nanocomposites

et al. 2021

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“…In stark contrast, by creating and manipulating the concave liquid bridges of evaporating droplets with confined geometries (e.g., capillary tube, [6] curve‐on‐flat geometry, [7] parallel‐plate geometry [8] ), functional nanomaterials (e.g., polymers, latex particles, nanoparticles, DNA, etc.) can be rapidly deposited into a set of intriguing large‐scale assemblies of different shapes in a one‐step manner [9–11] . Notably, such controlled evaporation of confined droplets invokes the tailoring of a three‐phase contact line (TCL) at the edge of the droplet (i.e., meniscus) via regulating the dimensions of the confined geometry, solution concentration, solvent characteristic, interfacial interaction between solute and substrate, etc [12, 13] …”

Section: Figurementioning

confidence: 99%

“…can be rapidly deposited into a set of intriguing large-scale assemblies of different shapes in a one-step manner. [9][10][11] Notably, such controlled evaporation of confined droplets invokes the tailoring of a three-phase contact line (TCL) at the edge of the droplet (i.e., meniscus) via regulating the dimensions of the confined geometry, solution concentration, solvent characteristic, interfacial interaction between solute and substrate, etc. [12,13] Among various conjugated polymers, blue-emitting PFOs have been widely recognized as an impressive model system that possesses rich yet peculiar crystal morphologies and polymorphisms, such as amorphous, semicrystalline a and a', and b phases, which can be preferentially accessed by different preparative routes.…”

mentioning

confidence: 99%

Large‐Scale Rapid Positioning of Hierarchical Assemblies of Conjugated Polymers via Meniscus‐Assisted Self‐Assembly

2021

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Rapid and deliberate patterning of nanomaterials over a large area is desirable for device manufacturing. We report a method for meniscus‐assisted self‐assembly (MASA)‐enabled rapid positioning of hierarchically assembled dots and stripes composed of luminescent conjugated polymer over two length scales. Periodically arranged conjugated poly(9,9‐dioctylfluorene) (PFO) polymers, yield dots, punch‐holes and stripes at microscopic scale via MASA. Concurrent self‐assembly of PFOs into two‐dimensional lenticular crystals within each dot, punch‐hole and stripe is realized at nanoscopic scale. Hierarchical assembly is achieved by constraining the evaporation of the PFOs solution in two approximately parallel plates via a MASA process. The three‐phase contact line (TCL) of the liquid meniscus of the PFOs was printed using the upper plate, yielding an array of curved stripes. Rapid creation of hierarchical assemblies via MASA opens up possibilities for large‐scale organization of a wide range of soft matters and nanomaterials.

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“…The MASP strategy was also used in other areas and shows great potential. [95][96][97][98] Lin et al made perovskite films with large grains, yielding a 17.51% PCE.…”

Section: Meniscus-assisted Solution-printingmentioning

confidence: 99%

Large‐Area Blade‐Coated Solar Cells: Advances and Perspectives

Xiao

Zuo

Zhong

et al. 2021

Advanced Energy Materials

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the representative of the third-generation photovoltaics, have attracted great attention owing to unique properties such as light weight, flexibility, low cost, and low-temperature solution process. PCE of OSCs has been greatly improved via continuous development of novel semiconducting materials and performance optimization in the past two decades. [3][4][5] Lead halide perovskites, as star semiconducting materials, have obtained enormous attention in optoelectronic fields due to their outstanding properties, such as, tunable band gaps, high absorption coefficient, high charge carrier mobility, and long carrier diffusion lengths. [6][7][8][9][10][11] Until 2021, PCEs of perovskite/silicon tandem cells and OSCs have exceeded 29% and 18%, respectively. [12][13][14] However, the high-efficiency cells are usually prepared by spin-coating, with an active area of less than 0.1 cm 2 . There is no doubt that the development of OSCs and PSCs will go to large-scale industrial production, thus the challenge is achieving large-area uniform active layers. However, due to the uneven centrifugal force in the traditional spin-coating process, the thicknesses at the center and the edge of the substrate is different, especially for large-area films. The thick area shows increased nonradiative recombination loss. The thin area shows reduced lightharvesting ability and increased pinholes, leading to reduced efficiency. To address these issues, developing large-area coating methods is an effective way. [15] So far, various methods have been applied to large-area film fabrication, including spray coating, [16][17][18][19] dip coating, [20,21] slot-die coating, [22,23] and bladecoating. Among these techniques, blade-coating has achieved the greatest success, with the best PCE of ≈22%.In this review, we summarize the recent advances of bladecoating techniques for fabricating large-area PSCs and OSCs, and analyze the issues that need to be solved in blade-coating technology. We hope it can provide new strategies for the commercialization of the third-generation solar cells. Blade-Coating TechnologyBlade-coating is a widely recognized method for the preparation of large-area films. Blade-coating method, with the merits of efficient material utilization, in situ crystallization and adjustable parameters, has been investigated in depth for the preparation of various thin films. [15] Figure 1 demonstrates the High-efficiency perovskite solar cells (PSCs) and organic solar cells (OSCs) are promising alternatives for silicon-based solar cells. At present, the key point for commercialization of PSCs and OSCs is realizing large-scale production while maintaining the same high efficiency as small-area ones. In this review, the blade-coating method for preparing large-area films is introduced first and the recent advances of blade-coated OSCs and PSCs are summarized. Then, the effects of blading parameters on the crystal growth and film formation of the light-harvesting materials are discussed. Moreover, the limitations and advantages of making h...

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Strongly-ligated perovskite quantum dots with precisely controlled dimensions and architectures for white light-emitting diodes

Cited by 55 publications

References 49 publications

Recent Advances in Synthesis, Properties, and Applications of Metal Halide Perovskite Nanocrystals/Polymer Nanocomposites

Recent Advances in Synthesis, Properties, and Applications of Metal Halide Perovskite Nanocrystals/Polymer Nanocomposites

Large‐Scale Rapid Positioning of Hierarchical Assemblies of Conjugated Polymers via Meniscus‐Assisted Self‐Assembly

Large‐Area Blade‐Coated Solar Cells: Advances and Perspectives

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