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

Abstract

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...

Design of two-dimensional halide perovskite composites for optoelectronic applications and beyond

“…Organic materials have also been widely used to couple with 2D perovskites. 53 Compared with inorganic materials, organic materials can make use of their own hydrophobic interaction to reduce the contact between perovskite nanocrystals and the external environment and thus increase perovskite stability. Perovskites can also be modified by functional organic molecules (such as strong electron donor or acceptor) to contribute directly to the electron band and thus promote charge separation.…”

Emerging New‐Generation Detecting and Sensing of Metal Halide Perovskites

“…With the rapid development of nanodrug delivery technology, luminescent probes are necessary in monitoring tumour-targeted drug delivery. [165][166][167] Compared with other luminescent materials, MHP nanoparticles have been regarded as next-generation biomedical optical probes that target cancer cells due to their excellent water [4,168] and thermal stabilities, [67] good acid and alkali resistances, biocompatibility [154] with a core-shell structure, and outstanding all-optical and photoluminescence (PL) properties. MHP luminescent probes are promising in realizing the full monitoring of nano-drug delivery systems.…”

Spontaneous Formation of Lead‐Free Cs3Cu2I5 Quantum Dots in Metal–Organic‐Frameworks with Deep‐Blue Emission

“…[ 6 ] However, the toxicity of lead and the poor stability against light, moisture, and heat remain challenges for perovskite QDs. [ 7 ] To address these issues, replacing lead with other divalent nontoxic elements is feasible. [ 8 ] Nevertheless, limited by the instability of tin or germanium, other low‐dimensional lead‐free metal halide perovskite QDs can be considered promising candidates.…”