A dπ-pπ Conjugated System with High Mobility and Strong Emission Simultaneously

Strong intermolecular interactions usually facilitate charge transport, but impede photoluminescence, therefore, the development of organic π-conjugated materials that exhibit both semiconducting and light-emissive properties remains challenging. Herein, a series of perylene diimide (PDI)-based carbolong complexes with d_π-p_π conjugation is synthesized. The resulting alcohol-soluble products exhibit broad and strong absorption combined with outstanding electronic and optical properties, and are applied as electron transport layer materials in organic solar cells, achieving power conversion efficiencies up to 17.36%. In addition, these complexes exhibit an uncommon aggregation-induced emission phenomenon. These results will aid in future design of π-conjugated materials with increased functionality.     

Solventless Acid‐Free Synthesis of Mesostructured Titania: Nanovessels for Metal Complexes and Metal Nanoclusters

A new and highly reproducible method to obtain mesostructured titania materials is introduced in this contribution. The mesostructured titania is obtained by employing self‐assembled structures of non‐ionic alkyl‐poly(ethylene oxide) surfactants as templates. The materials are produced without additional solvents such as alcohols, or even water. Only the titanium(IV ) ethoxide and the surfactant (C₁₂EO₁₀) are needed. Water, in the form of that attached to the surfactant and from the atmosphere, induces growth of titania nanoclusters in the synthesis sol. It is indicated that these nanoclusters interact with the surfactant EO‐head groups to form a new titanotropic amphiphile. The new amphiphiles self‐assemble into titanium nanocluster–surfactant hybrid lyotropic phases, which are transformed to the final mesostructured materials by further condensation of the titania network. The titania materials can be obtained also with noble‐metal particles immobilized in the mesostructured framework. It is seen that when different metal salts are used as the metal precursors, different interactions with the titania walls are found. The materials are characterized by X‐ray diffraction (XRD), polarization optical microscopy (POM), transmission electron microscopy (TEM), UV‐vis spectroscopy, and micro‐Raman analysis.     

Sensitization of Er3+ Infrared Photoluminescence Embedded in a Hybrid Organic‐Inorganic Copolymer containing Octahedral Molybdenum Clusters

Luminescent hybrid copolymers are obtained by copolymerizing in bulk methylmethacrylate with a methacrylic acid (MAC) solution containing [n‐Bu₄N]₂[Mo₆Br₈(MAC)₆], and aliquots of an Er(TMHD)₃ complex (TMHD for 2,2,6,6‐tetramethyl‐3,5‐heptanedione) solution. This leads to novel homogeneous and transparent hybrid materials in which the Er³⁺ infrared luminescence at 1.55 μm, a standard wavelength for telecommunication applications, is up to six time more intense in the presence of Mo₆ clusters when samples are irradiated at 476.5 nm. This work demonstrates the outstanding potential of Mo₆ clusters, compounds obtained by high‐temperature solid‐state synthesis, in the design of functional hybrid materials via soft chemistry routes.     

Visible and NIR Upconverting Er3+–Yb3+ Luminescent Nanorattles and Other Hybrid PMO‐Inorganic Structures for In Vivo Nanothermometry

Lanthanide‐doped luminescent nanoparticles are an appealing system for nanothermometry with biomedical applications due to their sensitivity, reliability, and minimal invasive thermal sensing properties. Here, four unique hybrid organic–inorganic materials prepared by combining β‐NaGdF₄ and PMOs (periodic mesoporous organosilica) or mSiO₂ (mesoporous silica) are proposed. PMO/mSiO₂ materials are excellent candidates for biological/biomedical applications as they show high biocompatibility with the human body. On the other hand, the β‐NaGdF₄ matrix is an excellent host for doping lanthanide ions, even at very low concentrations with yet very efficient luminescence properties. A new type of Er³⁺–Yb³⁺ upconversion luminescence nanothermometers operating both in the visible and near infrared regime is proposed. Both spectral ranges permit promising thermometry performance even in aqueous environment. It is additionally confirmed that these hybrid materials are non‐toxic to cells, which makes them very promising candidates for real biomedical thermometry applications. In several of these materials, the presence of additional voids leaves space for future theranostic or combined thermometry and drug delivery applications in the hybrid nanostructures.     

Synthesis and Characterization of Red‐Emitting Iridium(III) Complexes for Solution‐Processable Phosphorescent Organic Light‐Emitting Diodes

A new series of highly efficient red‐emitting phosphorescent Ir(III) complexes, (Et‐CVz‐PhQ)₂Ir(pic‐N‐O), (Et‐CVz‐PhQ)₂Ir(pic), (Et‐CVz‐PhQ)₂Ir(acac), (EO‐CVz‐PhQ)₂Ir(pic‐N‐O), (EO‐CVz‐PhQ)₂Ir(pic), and (EO‐CVz‐PhQ)₂Ir(acac), based on carbazole (CVz)‐phenylquinoline (PhQ) main ligands and picolinic acid N‐oxide (pic‐N‐O), picolinic acid (pic), and acetylacetone (acac) ancillary ligands, are synthesized for phosphorescent organic light‐emitting diodes (PhOLEDs), and their photophysical, electrochemical, and electroluminescent (EL) properties are investigated. All of the Ir(III) complexes have high thermal stability and emit an intense red light with an excellent color purity at CIE coordinates of (0.65,0.34). Remarkably, high‐performance solution‐processable PhOLEDs were fabricated using Ir(III) complexes with a pic‐N‐O ancillary ligand with a maximum external quantum efficiency (5.53%) and luminance efficiency (8.89 cd A^?1). The novel use of pic‐N‐O ancillary ligand in the synthesis of phosphorescent materials is reported. The performance of PhOLEDs using these Ir(III) complexes correlates well with the results of density functional theory calculations.     

Metal–Organic Framework (MOF) Derived Electrodes with Robust and Fast Lithium Storage for Li‐Ion Hybrid Capacitors

Hybrid metal–organic frameworks (MOFs) demonstrate great promise as ideal electrode materials for energy‐related applications. Herein, a well‐organized interleaved composite of graphene‐like nanosheets embedded with MnO₂ nanoparticles (MnO₂@C‐NS) using a manganese‐based MOF and employed as a promising anode material for Li‐ion hybrid capacitor (LIHC) is engineered. This unique hybrid architecture shows intriguing electrochemical properties including high reversible specific capacity 1054 mAh g^?1 (close to the theoretical capacity of MnO₂, 1232 mAh g^?1) at 0.1 A g^?1 with remarkable rate capability and cyclic stability (90% over 1000 cycles). Such a remarkable performance may be assigned to the hierarchical porous ultrathin carbon nanosheets and tightly attached MnO₂ nanoparticles, which provide structural stability and low contact resistance during repetitive lithiation/delithiation processes. Moreover, a novel LIHC is assembled using a MnO₂@C‐NS anode and MOF derived ultrathin nanoporous carbon nanosheets (derived from other potassium‐based MOFs) cathode materials. The LIHC full‐cell delivers an ultrahigh specific energy of 166 Wh kg^?1 at 550 W kg^?1 and maintained to 49.2 Wh kg^?1 even at high specific power of 3.5 kW kg^?1 as well as long cycling stability (91% over 5000 cycles). This work opens new opportunities for designing advanced MOF derived electrodes for next‐generation energy storage devices.     

One‐Step Synthesis and Optical Properties of Benzoate‐ and Biphenolate‐Capped ZrO2 Nanoparticles

A simple one‐pot approach based on the “benzyl alcohol route” is used for the preparation of benzoate‐ and biphenolate‐capped zirconia and, benzoate‐capped Eu‐doped zirconia nanoparticles. Powder X‐ray diffraction studies and high‐ resolution transmission electron microscopy (HR‐TEM) showed that the nanoparticles present high crystallinity and uniform particle sizes ranging from 3 to 4 nm. FT‐IR and solid state NMR (SS‐NMR) studies revealed that the nanoparticles are coated with a large amount of organic species when the reaction temperature is above 300 °C. It was found that the alcohol used as solvent is oxidized at the surface of the nanoparticles to the respective carboxylic acid which acts as a stabilizer, controlling the nanoparticles growth. The optical properties of these hybrid nanoparticles were studied by room and low (12K) temperature photoluminescence spectroscopy, time‐resolved spectroscopy and absolute emission quantum yield. The as‐synthesized benzoate‐ and biphenolate‐capped nanoparticles exhibit interesting emission properties in the UV and blue spectral regions together with values of emission quantum yields much higher than those reported for zirconia nanoparticles of similar size. The photoluminescent properties were attributed to a cooperative effect of the capping ligands and the defects associated to the ZrO₂ nanoparticles. Due to the overlapping of the various emission components involved (i.e., the emission of europium(III) intra‐4f⁶ transitions, defects in the zirconia and capping ligands) a tunable emission color ranging from purplish‐pink to greenish‐blue could be obtained for the europium‐doped zirconia nanoparticles by simply selecting different excitation wavelengths.     

New Inorganic–Organic Hybrid Materials for HPLC Separation Obtained by Direct Synthesis in the Presence of a Surfactant

Nanostructured, mesoporous inorganic–organic hybrid xerogels were reproducibly synthesized by a sol–gel procedure. For the introduction of long alkyl chains into inorganic polymers, trifunctional n‐alkyltrialkoxysilanes of the type CH₃(CH₂)_nSi(OR)₃ (n = 7, 11, 17; R = CH₃, C₂H₅) were co‐condensed with Si(OEt)₄ (TEOS). The synthetic pathway involves the employment of n‐hexadecylamine as template and catalyst. The xerogels obtained by the present procedure consist of uniform spherical particles with a diameter of about 1 μm. The composition of the new materials was determined by ¹³C and ²⁹Si cross polarization magic angle spinning (CP/MAS) NMR spectroscopy. In addition, the degree of organization was investigated by small angle X‐ray and electron diffraction. In accordance with ¹³C CP/MAS NMR spectroscopic measurements, the alkyl chains form a crystalline arrangement within the silica polymer. Brunauer–Emmett–Teller (BET) adsorption measurements confirm specific surface areas of up to 1400 m²/g. The material properties prove the xerogels to be suitable as stationary phases in high‐performance liquid chromatography (HPLC). These novel mesoporous, nanostructured materials have been successfully employed in HPLC for the first time. Different standard reference materials (SRMs) containing polycyclic aromatic hydrocarbons have been separated with the xerogels described in the present work.     

Screening Approach for the Discovery of New Hybrid Perovskites with Efficient Photoemission

Owing to quantum confinement, low‐dimensional hybrid perovskite materials have recently shown a great potential for applications in optoelectronics. Such compounds can exhibit broad‐ or narrow‐band light emission, low‐temperature solution processability, high thermal stability, and relatively high photoluminescence quantum yields (PLQY). However, the search for efficient phosphors with a specific set of characteristics remains difficult because the family of hybrid perovskites consists in an extremely large chemical system (i.e., different halides, metals, and organic molecules), and optical properties are not predictable prior to material synthesis and characterization. Here, is proposed a simple approach to screen a significant amount of new hybrid lead halide perovskites. The synthetic method by fast crystallization at low temperature enables the rapid identification of the materials exhibiting the targeted photoluminescence properties. This approach is tested for the discovery of hybrid lead halide perovskites with efficient white‐light emission. Among 100 newly synthesized compounds, 5 exhibit intense white emission, and the in‐depth characterization of a selected candidate shows high color rendering index (CRI) = 78 and a PLQY of 9%, which is equivalent to the record reported for hybrid perovskites. This compound exhibits a new structure type for warm white‐light emitting hybrid perovskites with chains of corner‐sharing PbX₆.     

Synthesis–Structure–Property Relationships for Hyperbranched Aminosilica CO2 Adsorbents

Hyperbranched aminosilica (HAS) adsorbents are prepared via the ring‐opening polymerization of aziridine in the presence of mesoporous silica SBA‐15 support. The aminopolymers are covalently bound to the silica support and capture CO₂ reversibly in a temperature swing process. Here, a range of HAS materials are prepared with different organic loadings. The effects of organic loading on the structural properties and CO₂ adsorption properties of the resultant hybrid materials are examined. The residual porosity in the HAS adsorbents after organic loading, as well as the molecular weights and degrees of branching for the separated aminopolymers, are determined to draw a relationship between adsorbent structure and performance. Humid adsorption working capacities and apparent adsorption kinetics are determined from experiments in a packed‐bed flow system monitored by mass spectrometry. Dry adsorption isotherms are presented for one HAS adsorbent with a high amine loading at 35 and 75 °C. These combined results establish the relationships between adsorbent synthesis, structure, and CO₂ adsorption properties of the family of HAS materials.     

Massive Anisotropic Thermal Expansion and Thermo‐Responsive Breathing in Metal–Organic Frameworks Modulated by Linker Functionalization

Functionalized metal–organic frameworks (fu‐MOFs) of general formula [Zn₂(fu‐L)₂dabco]_n show unprecedentedly large uniaxial positive and negative thermal expansion (fu‐L = alkoxy functionalized 1,4‐benzenedicarboxylate, dabco = 1,4‐diazabicyclo[2.2.2]octane). The magnitude of the volumetric thermal expansion is more comparable to property of liquid water rather than any crystalline solid‐state material. The alkoxy side chains of fu‐L are connected to the framework skeleton but nevertheless exhibit large conformational flexibility. Thermally induced motion of these side chains induces extremely large anisotropic framework expansion and eventually triggers reversible solid state phase transitions to drastically expanded structures. The thermo‐responsive properties of these hybrid solid–liquid materials are precisely controlled by the choice and combination of fu‐Ls and depend on functional moieties and chain lengths. In principle, this combinatorial approach allows for a targeted design of extreme thermo‐mechanical properties of MOFs addressing the regime between crystalline solid matter and the liquid state.     

Revealing the Interplay between Charge Transport,Luminescence Efficiency,and Morphology in Organic Light‐Emitting Diode Blends

Phosphorescent emissive materials in organic light‐emitting diodes (OLEDs) manufactured using evaporation are usually blended with host materials at a concentration of 3–15 wt% to avoid concentration quenching of the luminescence. Here, experimental measurements of hole mobility and photoluminescence are related to the atomic level morphology of films created using atomistic nonequilibrium molecular dynamics simulations mimicking the evaporation process with similar guest concentrations as those used in operational test devices. For blends of fac‐tris[2‐phenylpyridinato‐C2,N]iridium(III) [Ir(ppy)₃] in tris(4‐carbazoyl‐9‐ylphenyl)amine (TCTA), it is found that clustering of the Ir(ppy)₃ (surface of the molecules within ≈0.4 nm) in the simulated films is directly relatable to the experimentally‐measured hole mobility. Films containing 1–10 wt% of Ir(ppy)₃ in TCTA have a mobility of up to two orders of magnitude lower (≈10^?6 cm² V^?1 s^?1) than the neat TCTA film, which is consistent with the Ir(ppy)₃ molecules acting as hole traps due to their smaller ionization potential. Comparison of the simulated film morphologies with the measured photoluminescence properties shows that for luminescence quenching to occur, the Ir(ppy)₃ molecules have to have their ligands partially overlapping. Thus, the results show that the effect of guest interactions on charge transport and luminescence are markedly different for OLED light‐emitting layers.     

Synthesis and Characterization of Bifunctionalized Ordered Mesoporous Materials

Direct synthesis (co‐condensation reaction) and post‐synthesis reaction (grafting) are combined for the first time to efficiently fabricate bifunctionalized ordered mesoporous materials (OMMs). Ethylenediamine‐containing OMMs (ED‐MCM‐41) were first synthesized via direct synthesis and then further modified by the phenyl (PH) group in a supercritical fluid (SCF) medium via grafting reaction, resulting in OMMs with ED and PH groups (PH‐ED‐MCM‐41). X‐ray diffraction (XRD) patterns, N₂ sorption properties, transmission electron microscopy (TEM), ²⁹Si and ¹³C magic angle spinning (MAS) NMR, chemical analysis, and hydrothermal treatment were used to characterize the bifunctionalized materials. Experiments show that bifunctionalized OMMs can be efficiently prepared by modifying the directly synthesized monofunctionalized OMMs via grafting reaction in a supercritical fluid medium. Both functional groups are distributed uniformly at the surfaces. The advantage of bifunctionalized OMMs over monofunctionalized OMMs was illustrated by introducing thiol groups into ED‐MCM‐41 materials and the subsequent formation of CdS nanocrystals inside thiol‐ and ED‐functionalized MCM‐41 (HS‐ED‐MC‐41). Because of the variety of the functional groups that can be introduced into OMMs by direct synthesis or post‐synthesis reaction, it is expected that the present strategy could provide a generally applicable approach to the design of OMMs with two functional groups.     

Electrochromism of interpolyelectrolyte poly(pyridinium) – Poly(styrene sulfonate) complexes

This paper represents a synthesis method of both soluble and insoluble interpolyelectrolyte complexes due to interaction of poly(4,4-(1,4-phenylene)bis(2,6-diphenylpyridinium) triflate) (PV) and sodium polystyrene sulfonate (PSS). Systematic evaluation of electrochromic properties of the both type complexes is given compared to the pristine electrochromic PV. The complexes composition and properties were studied as a function of polyanion and polycation concentrations and their ratios. It was demonstrated that non-stoichiometric insoluble complexes PV/PSS with an excess of PSS are formed in the initial mutual solvent DMF/H₂O 5/1. Films prepared from that mixtures exhibit slower response times and deteriorated electrochromic stability. Non-stoichiometric interpolymer complexes PV/PSS with an excess of PV remain soluble in the initial solvent. Corresponding films have a superior electrochromic contrast than films obtained from the solution of pristine PV under identical conditions. Thus, optimum mixture ratios were found to obtain soluble interpolymer complexes with the advanced properties that may open up new possibilities for making novel electrochromic devices.     

Versatile,Benzimidazole/Amine‐Based Ambipolar Compounds for Electroluminescent Applications: Single‐Layer,Blue, Fluorescent OLEDs,Hosts for Single‐Layer,Phosphorescent OLEDs

A series of compounds containing arylamine and 1,2‐diphenyl‐1H‐benz[d]imidazole moieties are developed as ambipolar, blue‐emitting materials with tunable blue‐emitting wavelengths, tunable ambipolar carrier‐transport properties and tunable triplet energy gaps. These compounds possess several novel properties: (1) they emit in the blue region with high quantum yields; (2) they have high morphological stability and thermal stability; (3) they are capable of ambipolar carrier transport; (4) they possess tunable triplet energy gaps, suitable as hosts for yellow‐orange to green phosphors. The electron and hole mobilities of these compounds lie in the range of 0.68–144 × 10^?6 and 0.34–147 × 10^?6 cm² V^?1 s^?1, respectively. High‐performance, single‐layer, blue‐emitting, fluorescent organic light‐emitting diodes (OLEDs) are achieved with these ambipolar materials. High‐performance, single‐layer, phosphorescent OLEDs with yellow‐orange to green emission are also been demonstrated using these ambipolar materials, which have different triplet energy gaps as the host for yellow‐orange‐emitting to green‐emitting iridium complexes. When these ambipolar, blue‐emitting materials are lightly doped with a yellow‐orange‐emitting iridium complex, white organic light‐emitting diodes (WOLEDs) can be achieved, as well by the use of the incomplete energy transfer between the host and the dopant.     

Organic–Inorganic Hierarchical Self‐Assembly into Robust Luminescent Supramolecular Hydrogel

Luminescent hydrogels are of great potential for many fields, particularly serving as biomaterials ranging from fluorescent sensors to bioimaging agents. Here, robust luminescent hydrogels are reported using lanthanide complexes as emitting sources via a hierarchical organic–inorganic self‐assembling strategy. A new organic ligand is synthesized, consisting of a terpyridine unit and two flexibly linked methylimidazole moieties to coordinate with europium(III) (Eu³⁺) tri‐thenoyltrifluoroacetone (Eu(TTA)₃), leading to a stable amphiphilic Eu³⁺‐containing monomer. Synergistic coordination of TTA and terpyridine units allows the monomer to self‐assemble into spherical micelles in water, thus maintaining the luminescence of Ln complexes in water. The micelles further coassemble with exfoliated Laponite nanosheets coated with sodium polyacrylate into networks based on the electrostatic interactions, resulting in the supramolecular hydrogel possessing strong luminescence, extraordinary mechanical property, as well as self‐healing ability. The results demonstrate that hierarchical organic–inorganic self‐assembly is a versatile and effective strategy to create luminescent hydrogels containing lanthanide complexes, giving rise to great potential applications as a soft material.     

Nanocomposite Hybrid Molecular Materials for Application in Solid‐State Electrochemical Supercapacitors

Molecular hybrid materials formed from polyoxometalates dispersed in conducting polymers represent an innovative concept in energy storage. This work reports in detail the first practical realization of electrodes based on these materials for energy storage in electrochemical supercapacitors. The molecular hybrids PAni/H₄SiW₁₂O₄₀, PAni/H₃PW₁₂O₄₀, and PAni/H₃PMo₁₂O₄₀ (PAni: polyaniline) have been prepared electrochemically on platinum or carbon substrates, with PAni/H₃PMo₁₂O₄₀ being the prototypical example presenting the best energy‐storage performance in the series. This hybrid displays the combined activity of its organic and inorganic components to store and release charge in solid‐state electrochemical capacitor cells, leading to a promising value of 120 F g^–1 and good cyclability beyond 1000 cycles.     

Irradiation of Transition Metal Dichalcogenides Using a Focused Ion Beam: Controlled Single‐Atom Defect Creation

Manipulation and structural modifications of 2D materials for nanoelectronic and nanofluidic applications remain obstacles to their industrial‐scale implementation. Here, it is demonstrated that a 30 kV focused ion beam can be utilized to engineer defects and tailor the atomic, optoelectronic, and structural properties of monolayer transition metal dichalcogenides (TMDs). Aberration‐corrected scanning transmission electron microscopy is used to reveal the presence of defects with sizes from the single atom to 50 nm in molybdenum (MoS₂) and tungsten disulfide (WS₂) caused by irradiation doses from 10¹³ to 10¹⁶ ions cm^?2. Irradiated regions across millimeter‐length scales of multiple devices are sampled and analyzed at the atomic scale in order to obtain a quantitative picture of defect sizes and densities. Precise dose value calculations are also presented, which accurately capture the spatial distribution of defects in irradiated 2D materials. Changes in phononic and optoelectronic material properties are probed via Raman and photoluminescence spectroscopy. The dependence of defect properties on sample parameters such as underlying substrate and TMD material is also investigated. The results shown here lend the way to the fabrication and processing of TMD nanodevices.     

Biocatalytic Nanoscale Coatings Through Biomimetic Layer‐by‐Layer Mineralization

Recent insight into the molecular mechanisms of biological mineral formation (biomineralization) has enabled biomimetic approaches for the synthesis of functional organic‐inorganic hybrid materials under mild reaction conditions. Here we describe a novel method for enzyme immobilization in thin (nanoscale) conformal mineral coatings using biomimetic layer‐by‐layer (LbL) mineralization. The method utilizes a multifunctional molecule comprised of a naturally‐occurring peptide, protamine (PA), covalently bound to the redox enzyme Glucose oxidase (GOx). PA mimics the mineralizing properties of biomolecules involved in silica biomineralization in diatoms, and its covalent attachment to GOx does not interfere with the catalytic activity. Highly efficient and stable incorporation of this modified enzyme (GOx‐PA) into nanoscale layers (～5–7 nm thickness) of Ti‐O and Si‐O is accomplished during protamine‐enabled LbL mineralization on silica spheres. Depending on the layer location of the enzyme and the type of mineral (silica or titania) within which the enzyme is incorporated, the resulting multilayer biocatalytic hybrid materials exhibit between 20–100% of the activity of the free enzyme in solution. Analyses of kinetic properties (V_max, K_M) of the immobilized enzyme, coupled with characterization of physical properties of the mineral‐bearing layers (thickness, porosity, pore size distribution), indicates that the catalytic activities of the synthesized hybrid nanoscale coatings are largely determined by substrate diffusion rather than enzyme functionality. The GOx‐PA immobilized in these nanoscale layers is substantially stabilized against heat‐induced denaturation and largely protected from proteolytic attack. The method for enzyme immobilization described here enables, for the first time, the high yield immobilization and stabilization of enzymes within continuous, conformal, and nanoscale coatings through biomimetic LbL mineralization. This approach will likely be applicable to a wide variety of surfaces and functional biomolecules. The ability to synthesize thin (nanoscale) conformal enzyme‐loaded layers is of interest for numerous applications, including enzyme‐based biofuel cells and biosensors.     

Nonlinear Absorption Applications of CH3NH3PbBr3 Perovskite Crystals

Researchers have recently revealed that hybrid lead halide perovskites exhibit ferroelectricity, which is often associated with other physical characteristics, such as a large nonlinear optical response. In this work, the nonlinear optical properties of single crystal inorganic–organic hybrid perovskite CH₃NH₃PbBr₃ are studied. By exciting the material with a 1044 nm laser, strong two‐photon absorption‐induced photoluminescence in the green spectral region is observed. Using the transmission open‐aperture Z‐scan technique, the values of the two‐photon absorption coefficient are observed to be 8.5 cm GW^?1, which is much higher than that of standard two‐photon absorbing materials that are industrially used in nonlinear optical applications, such as lithium niobate (LiNbO₃), LiTaO₃, KTiOPO₄, and KH₂PO₄. Such a strong two‐photon absorption effect in CH₃NH₃PbBr₃ can be used to modulate the spectral and spatial profiles of laser pulses, as well as to reduce noise, and can be used to strongly control the intensity of incident light. In this study, the superior optical limiting, pulse reshaping, and stabilization properties of CH₃NH₃PbBr₃ are demonstrated, opening new applications for perovskites in nonlinear optics.