Covalently bound hole-injecting nanostructures. Systematics of molecular architecture, thickness, saturation, and electron-blocking characteristics on organic light-emitting diode luminance, turn-on voltage, and quantum efficiency

Hole transporting materials are widely used in multilayer organic and polymer light-emitting diodes (OLEDs, PLEDs, respectively) and are indispensable if device electroluminescent response and durability are to be truly optimized. This contribution analyzes the relative effects of tin-doped indium oxide (ITO) anode-hole transporting layer (HTL) contact versus the intrinsic HTL materials properties on OLED performance. Two siloxane-based HTL materials, N,N'-bis(p-trichlorosilylpropyl)-naphthalen-1-yl)-N,N'-diphenyl-biphenyl-4,4'-diamine (NPB-Si(2)) and 4,4'-bis[(p-trichlorosilylpropylphenyl)phenylamino]biphenyl (TPD-Si(2)), are designed and synthesized. They have the same hole transporting triarylamine cores as conventional HTL materials such as 1,4-bis(1-naphthylphenylamino)biphenyl (NPB) and N,N-diphenyl-N,N-bis(3-methylphenyl)-1,1-biphenyl)-4,4-diamine (TPD), respectively. However, they covalently bind to the ITO anode, forming anode-HTL contacts that are intrinsically different from those of the anode to TPD and NPB. Applied to archetypical tris(8-hydroxyquinolato)aluminum(III) (Alq)-based OLEDs as (1) the sole HTLs or (2) anode-NPB HTL interlayers, NPB-Si(2) and TPD-Si(2) enhance device electroluminescent response significantly versus comparable devices based on NPB alone. In the first case, OLEDs with 36 000 cd/m(2) luminance, 1.6% forward external quantum efficiency (eta(ext)), and 5 V turn-on voltages are achieved, affording a 250% increase in luminance and approximately 50% reduction in turn-on voltage, as compared to NPB-based devices. In the second case, even more dramatic enhancement is observed (64 000 cd/m(2) luminance; 2.3% eta(ext); turn-on voltages as low as 3.5 V). The importance of the anode-HTL material contact is further explored by replacing NPB with saturated hydrocarbon siloxane monolayers that covalently bind to the anode, without sacrificing device performance (30 000 cd/m(2) luminance; 2.0% eta(ext); 4.0 V turn-on voltage). These results suggest new strategies for developing OLED hole transporting structures.     

多色高发光效率CsPbX3(X=Cl,Br,I)钙钛矿量子点的制备及其在发光二极管中的应用

采用室温合成法制备出一系列具有高发光效率和多色发光的CsPbX₃钙钛矿量子点(PQDs),反应全过程快速简便,且通过调节不同的卤素组成(Cl,Br,I)可以实现CsPbX₃ PQD的多色发光。 通过表征证明,CsPbX₃ PQDs呈立方晶型,平均粒径约为10 nm,发射光谱覆盖可见光波长范围为410~630 nm,半峰宽14~38 nm,荧光量子产率10%~90%。 最后将CsPbX₃ PQDs应用于发光二极管(LED)器件的制备中,在恒定电压下工作时,能保持LED器件的发光颜色、强度和颜色坐标不变。     

Organic Light Emitting Diodes with Lithium Contained Alq3 as Electron Injection Layer

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｏｒｇａｎｉｃｌｉｇｈｔｅｍｉｔｔｉｎｇｄｉｏｄｅ(ＯＬＥＤ) ,ｓｏｍｅｍｅｔａｌｓｗｉｔｈｌｏｗｗｏｒｋｆｕｎｃｔｉｏｎ ,ｓｕｃｈａｓａｌｌｏｙｏｆｍａｇ ｎｅｓｉｕｍａｎｄｓｉｌｖｅｒ(Ｍｇ∶Ａｇ) [1] ａｎｄａｌｕｍｉｎｉｕｍ[2 ] ,ａｒｅｕｓｅｄａｓｔｈｅｅｌｅｃｔｒｏｎｉｎｊｅｃｔｉｏｎｃａｔｈｏｄｅｓ .ＩｎＭｇ∶Ａｇａｌ ｌｏｙｓｉｌｖｅｒｉｓｕｓｅｄｔｏｐｒｏｔｅｃｔｍａｇｎｅｓｉｕｍｆｒｏｍｔｈｅｒｅａｃ ｔｉｏｎｏｆｍａｇｎｅｓｉｕｍｗｉｔｈｏｘｙｇｅｎａｎｄ…     

Polycyclic aromatic hydrocarbon-bridged coumarin derivatives for organic light-emitting devices

Three biscoumarin dyes bridged by polycyclic aromatic bridges (anthracen, pyrene and dibenzo[g,p]chrysene) were prepared as the emissive materials for the application of organic light-emitting devices. The relationship between their structures, photophysical properties, electrochemical properties and performances of organic light-emitting devices are described. The multilayered doped devices with a configuration of ITO/NPB (20 nm)/TBADN: biscoumarin compound (x wt%, 30 nm)/TPBi (30 nm)/Liq (2 nm)/Al (100 nm) have been successfully fabricated by vacuum-deposition method. All the devices showed green emission with high electroluminescent efficiencies. Especially, the device based on the compound containing pyrene as a bridge group at 7% doping concentration showed the best performance with a maximum brightness of 10552 cd/m², maximum luminous efficiency of 5.39 cd/A and maximum external quantum efficiency (EQE) of 2.35%.     

Mesoporous Silica Particles Integrated with All‐Inorganic CsPbBr3 Perovskite Quantum‐Dot Nanocomposites (MP‐PQDs) with High Stability and Wide Color Gamut Used for Backlight Display

All‐inorganic CsPbX₃ (X=I, Br, Cl) perovskite quantum dots (PQDs) have been investigated because of their optical properties, such as tunable wavelength, narrow band, and high quantum efficiency. These features have been used in light emitting diode (LED) devices. LED on‐chip fabrication uses mixed green and red quantum dots with silicone gel. However, the ion‐exchange effect widens the narrow emission spectrum. Quantum dots cannot be mixed because of anion exchange. We address this issue with a mesoporous PQD nanocomposite that can prevent ion exchange and increase stability. We mixed green quantum‐dot‐containing mesoporous silica nanocomposites with red PQDs, which can prevent the anion‐exchange effect and increase thermal and photo stability. We applied the new PQD‐based LEDs for backlight displays. We also used PQDs in an on‐chip LED device. Our white LED device for backlight display passed through a color filter with an NTSC value of 113 % and Rec. 2020 of 85 %.     

High-efficiency saturated red emission from binuclear cyclo-metalated platinum complex containing 5-(4-octyloxyphenyl)-1,3,4-oxadiazole-2-thiol ancillary ligand in PLED

A novel red-emitting binuclear platinum complex (dfppy)2Pt2(C8OXT)2 was synthesized and characterized,in which dfppy represents 2-(4’,6’-difluorophenyl)pyridinato unit and C8OXT is abbreviated for 5-(4-octyloxyphenyl)-1,3,4-oxadiazole-2-thiol as a bridging ancillary ligand.Its photophysical,electrochemical and electroluminescent characteristics were primarily studied.The made single-emissive-layer (SEL) polymer light-emitting devices using (dfppy)2Pt2(C8OXT)2 as emitter exhibited a saturated red emission peaked at 620nm.The best device performances were obtained in the device at 8wt% dopant concentration,with a maximum external quantum efficiency of 8.4%,a current efficiency of 4.2cd/A and brightness of 3228cd/m2.This work provides an effective approach to obtain high-efficiency red emission through construction of new binuclear platinum complex and its doped SEL devices.     

Organic light‐emitting device dark spot growth behavior analysis by diffusion reaction theory

Dark spot growth rate tracing experiments performed on an organic light‐emitting device show that moisture entering into the device is relatively properly fitted by Fick's diffusion equation in the substrate/indium tin oxide (ITO)/hole transport layer (HTL)/silver (Ag) structure. It is believed that the moisture is dissolved into the polymer layer, which results in a decrease in the diffusion coefficient in the device with the substrate/ITO/HTL/electroluminescent (EL) polymer/Ag structure. The diffusion and chemical reaction occurring in the cathode layer further decreases the diffusion coefficient in the device with the substrate/ITO/HTL/EL polymer/calcium/Ag structure. Useful parameters, such as diffusion and solubility constants, describing possible mechanisms happening during dark spot growth on organic light‐emitting diode devices are extracted. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1697–1703, 2001     

Organic electroluminescent devices containing phosphorescent molecules in molecularly doped hole transporting layer

We demonstrate high-efficient simple electrophosphorescent devices comprised of tris{4-[N-(3-methylphenyl)anilino]phenyl}amine (m-MTDATA) dispersed in a polycarbonate (PC) matrix as a hole-transporting layer (HTL), and 2-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) as an electron-transporting layer (ETL). The HTL doped with a complex phosphor fac-tris(2-phenylpyridine)iridium, [Ir(ppy)₃], and/or 5,6,11,12-tetraphenyltetracene (rubrene) fluorescent dye is shown to act as an emitter. Devices containing [Ir(ppy)₃] as a single HTL dopant show the highest external quantum efficiency (QE) reaching 9 % (photon/electron) due to direct electron-hole recombination on phosphorescent [Ir(ppy)₃]. A decrease in QE of one order of magnitude at high current densities is observed in all devices. Addition of rubrene to [Ir(ppy)₃]-doped devices shifts the maximum QE towards larger current densities.     

新型电磷光咔唑-co-吡啶共聚物的合成与发光性能

用Suzuki缩聚反应制备了一系列新型咔唑-吡啶共轭主链上含有金属铱配合物单元的共聚物. 共聚物发光器件结构为ITO/PEDOT:PSS/polymer＋PBD (w＝30%)/CsF/Al [氧化铟锡/苯磺酸掺杂聚乙烯基二氧噻吩/聚合物＋2,4-二苯-5-4-叔丁基苯-1,3,4-恶二唑(w＝30%)/氟化铯/铝]. 基于共聚物PCzPyIrMppy2的器件在电流密度为20.8 mA/cm2时, 最大外量子效率和流明效率分别达到4.1%和6.1 cd/A. 在电流密度200 mA/cm2时, 器件的最大外量子效率和流明效率仍分别达到3.2%和4.8 cd/A, 器件的发光的最大波长位于570 nm, 最大亮度达到13251 cd/m2. 研究结果表明, 在共轭聚合物主链上引入螯合金属铱配合单元是实现高效、稳定的电致磷光器件的有效方法之一.     

Modification of Hole Transport Layers for Fabricating High Performance Non‐fullerene Polymer Solar Cells

Interfacial engineering is expected to be a feasible strategy to improve the charge transport properties of the hole transport layer (HTL), which is of crucial importance to boost the device performance of organic solar cells (OSCs). In this study, two types of alcohol soluble materials, 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F₄‐TCNQ) and di‐tetrabutylammoniumcis–bis(isothiocyanato)bis (2,2’‐bipyridyl‐4,4’‐dicarboxylato) ruthenium(II) (N719) dye were selected as the dopant for HTL. The doping of F₄‐TCNQ and N719 dye in poly (ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) with and without integrating a graphene quantum‐dots (G‐QDs) layer has been explored in poly[[2,6′‐4‐8‐di(5‐ethylhexylthienyl)benzo[1,2‐b:3,3‐b]dithiophene][3‐fluoro‐2[(2‐ethylhexyl)carbonyl]thieno[3,4‐b]thio‐phenediyl:(2,2′‐((2Z,2′Z)‐(((4,4,9, 9‐tetrakis(4‐hexylphenyl)‐4,9‐dihydro‐s‐indaceno[1,2‐b:5,6‐b′]dithiophene‐2,7‐diyl)bis(4‐((2‐ethylhexyl)oxy)thiophene‐5,2‐diyl))bis(methanylylidene))bis(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐indene‐2,1‐diylidene))dimalononitrile (PTB7‐Th:IEICO‐4F) OSCs. The power conversion efficiency of the non‐fullerene OSCs has been increased to 10.12% from 8.84%. The influence of HTL modification on the nano‐morphological structures and photophysical properties is analyzed based on the comparative studies performed on the control and modified devices. The use of chemical doping and bilayer strategy optimizes the energy level alignment, nanomorphology, hole mobility, and work‐function of HTL, leading to considerable reduction of the leakage current and recombination losses. Our work demonstrates that the doping of HTL and the incorporation of G‐QDs layer to constitute a bilayer HTL is an promising strategy to fabricate high performance non‐fullerene polymer solar cells     

High‐efficiency organic electroluminescent devices using iridium complex emitter and arylamine‐containing polymer buffer layer

We have developed efficient organic electroluminescent (EL) devices using a phosphorescent material, tris(2‐phenylpyridine) iridium, Ir(ppy)₃, as an emitter material and a polymer buffer layer, tetraphenyldiamine‐containing poly(arylene ether sulfone) (PTPDES) doped with tris(4‐bromophenyl) aminium hexachloroantimonate (TBPAH) as an electron acceptor. In this device, a high external quantum efficiency of 21.6% and a luminous efficiency of 82 lm/W (77 cd/A) at 3.0 V were obtained. These high efficiencies can be explained by high quantum efficiency due to phosphorescent Ir(ppy)₃ and high luminous efficiency realized by the use of the polymer buffer layer. Copyright © 2002 John Wiley & Sons, Ltd.     

Efficient Non‐doped Blue Fluorescent Organic Light‐Emitting Diodes Based on Anthracene–Triphenylethylene Derivatives

The development of efficient blue materials has been a continuous research topic in the field of organic light‐emitting diodes (OLEDs). In this paper, three aggregation‐induced emission enhancement active blue emitters, PIAnTPE, TPAAnTPE and CzAnTPE, are successfully synthesized by attaching a triphenylethylene unit and phenanthroimidazole/triphenylamine/carbazole moieties to the 9,10‐positions of anthracene, respectively. The three compounds exhibit good thermal stabilities, appropriate for the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels and display high photoluminescence quantum yields (PLQYs) of 65, 70 and 46 % in the solid state. Non‐doped blue devices using PIAnTPE, TPAAnTPE and CzAnTPE as the emitting layers show good electroluminescent performances, with the maximum external quantum efficiencies (EQEs) of 4.46, 4.13 and 4.04 %, respectively. More importantly, EQEs of all the three devices can be still retained when the luminescence reaches 1000 cd m^?2, exhibiting quite small efficiency roll‐offs in the non‐doped OLEDs.     

High‐Performance Non‐doped OLEDs with Nearly 100 % Exciton Use and Negligible Efficiency Roll‐Off

Non‐doped organic light‐emitting diodes (OLEDs) possess merits of higher stability and easier fabrication than doped devices. However, luminescent materials with high exciton use are generally unsuitable for non‐doped OLEDs because of severe emission quenching and exciton annihilation in neat films. Herein, we wish to report a novel molecular design of integrating aggregation‐induced delayed fluorescence (AIDF) moiety within host materials to explore efficient luminogens for non‐doped OLEDs. By grafting 4‐(phenoxazin‐10‐yl)benzoyl to common host materials, we develop a series of new luminescent materials with prominent AIDF property. Their neat films fluoresce strongly and can fully harvest both singlet and triplet excitons with suppressed exciton annihilation. Non‐doped OLEDs of these AIDF luminogens exhibit excellent luminance (ca. 100000 cd m^?2), outstanding external quantum efficiencies (21.4–22.6 %), negligible efficiency roll‐off and improved operational stability. To the best of our knowledge, these are the most efficient non‐doped OLEDs reported so far. This convenient and versatile molecular design is of high significance for the advance of non‐doped OLEDs.     

Syntheses,structures, and electroluminescence of Ln(2)(acac-azain)(4)(mu-acac-azain)(2) [acac-azain = 1-(N-7-azaindolyl)-1,3-butanedionato,Ln = Tb(III) and Y(III)

Two new luminescent lanthanide complexes Ln(2)(acac-azain)(4)(mu-acac-azain)(2) [acac-azain = 1-(N-7-azaindolyl)-1,3-butanedionato, Ln = Tb(III), 1, Y(III), 2] have been synthesized and structurally characterized. These two dinuclear complexes are isostructural with the two lanthanide ions being bridged by two acac-azain ligands. Each of the two metal ions is further chelated by four oxygen atoms from two acac-azain ligands, resulting in a coordination number eight for each metal ion. 1 displays characteristic Tb(III) emission bands while 2 displays weak blue luminescence attributable to the ligand. Single-layer and double-layer electroluminescent devices for compound 1 were fabricated, where compound 1 doped PVK layer functions as both the emitting layer and the hole transport layer and PBD functions as an electron transport layer (in the double-layer device), demonstrating that compound 1 is a promising green emitter in electroluminescent devices.     

In-situ synthesis of stable perovskite quantum dots in core-shell nanofibers via microfluidic electrospinning

Perovskite quantum dots (PQDs) possess remarkable optical properties, such as tunable photoluminescence (PL) emission spectra, narrow full width at half maximum (FWHM) and high PL quantum yield (QY), endowing the PQDs great application prospects. However, the inherent structural instability of PQDs has seriously hindered the application of PQDs in various photoelectric devices. In this work, a microfluidic electrospinning method was used to fabricate color-tunable fluorescent formamidinium lead halogen (FAPbX₃, X = Cl, Br, I) PQDs/polymer core-shell nanofiber films. The core-shell spinning nanofiber not only supplies the interspace for the in-situ formation of PQDs, but also significantly reduces the permeability of moisture and oxygen in the air, which greatly improves the stability of PQDs. After adjusting the composition of precursors, the blue-emissive polystyrene (core) and polymethyl methacrylate (shell) coated FAPbCl₃ QDs (abbreviated as PS/FAPbCl₃/PMMA, hereinafter), green-emissive PS/FAPbBr₃/PMMA and red-emissive PS/FAPbI₃/PMMA nanofiber films were fabricated with the highest PL QY of 82.3%. Moreover, the PS/FAPbBr₃/PMMA nanofiber film exhibits great PL stability under blue light irradiation, long-term storage in the air and water resistance test. Finally, the green- and red-emissive nanofiber films were directly applied as light conversion films to fabricate wide-color-gamut display with the color gamut of 125%, indicating their tremendous potentials in optoelectronic applications.     

Controllable Optical,Electrical, and Morphologic Properties of 3,4‐Ethylenedioxythiophene Based Electrocopolymerization Films

This contribution presents a kind of novel and neutral network films based on EDOT formed by in situ electrocopolymerization (ECP). The ECP films which are neutral and colorless exhibit the conductivity of 0.2–0.5 S · cm⁻¹, W_F of 4.79–5.20 eV, and RMS roughness of 3.51–5.26 nm. The electroluminescent devices where ECP films acted as hole‐transport layer (HTL) exhibit higher brightness, current density, efficiency (20–30% improvement), and stability than that of PEDOT:PSS HTL device. The ECP films also significantly benefit the stability of neighboring organic layer compared to PEDOT:PSS. This kind of new ECP films affords more opportunities to develop organic light‐emitting diodes (OLEDs) with high performances and stability.

     

Bright Luminous and Stable CsPbBr3@PS Microspheres Prepared via Facile Anti-solvent Method using CTAB as Double Modifier

The past decade has witnessed the increasing interest in cesium lead halide perovskite quantum dots (PQDs) for their excellent optical properties with higher photoluminescence efficiency and tunable emission wavelengths widely applied in white LED, photovoltaic devices, etc. Here we report the preparation of CsPbBr₃ PQDs by a facile anti-solvent method using conventional quaternary ammonium bromide (CTAB) as a double modifier—both proper alkyl group protection and bromine source donator. The as-formed PQDs are well-monodispersed cubes with a size of 10–15 nm and high photoluminescence quantum yield (PLQY) of up to 43 %. To enhance the stability of PQDs, CsPbBr₃@PS microspheres were formed by electrospraying process. The microspheres not only show excellent luminous properties, but exhibit much higher stability against air and UV light irradiation due to the super hydrophobic property of polystyrene.     

Organometallic complexes as hole-transporting materials in organic light-emitting diodes

The use of metal complexes fac-tris(1-phenylpyrazolato-N,C(2)('))cobalt(III) [fac-Co(ppz)(3)], fac-tris(2-phenylpyridinato-N,C(2)(') cobalt(III) [fac-Co(ppy)(3)], and [tris[2-((pyrrole-2-ylmethylidene)amino)ethyl]amine]gallium(III) [Ga(pma)] as materials for hole-transporting layers (HTL) in organic light-emitting diodes (OLEDs) is reported. Co(ppz)(3) and Co(ppy)(3) were prepared by following literature procedures and isolated as mixtures of facial (fac) and meridional (mer) isomers. The more stable fac isomers were separated from the unstable mer forms via column chromatography and thermal gradient sublimation. Crystals of fac-Co(ppz)(3) are monoclinic, space group P2(1)/c, with a = 13.6121(12) A, b = 15.5600(12) A, c = 22.9603(17) A, beta = 100.5 degrees, V = 4781.3(7) A(3), and Z = 8. [Tris[2-((pyrrol-2-ylmethylidene)amino)ethyl]amine]gallium [Ga(pma)] was prepared by the reaction of gallium(III) nitrate with the pmaH(3) ligand precursor in methanol. Ga(pma) crystallizes in the cubic space group I3d with cell parameters a = 20.2377(4) A, b = 20.2377(4) A, c = 20.2377(4) A, beta = 90.0 degrees, V = 8288.6(3) A(3), and Z = 16. These cobalt and gallium complexes are pale colored to colorless solids, with optical energy gaps ranging 2.6-3.36 eV. A two-layer HTL/ETL (ETL = electron-transporting layer) device structure using fac-Co(ppz)(3) and fac-Co(ppy)(3) as the HTL does not give efficient electroluminescence. However, the introduction of a thin layer of a hole-transporting material (N,N'-bis(1-naphthyl)-N,N'-diphenylbenzidine, NPD) as an energy "stair-step" and electron/exciton-blocker dramatically improves the device performance. Both fac-Co(ppz)(3) and fac-Co(ppy)(3) devices give external quantum efficiencies higher than 1.0%, with brightness 5000 and 7000 Cd/m(2) at 10 V, respectively. Ga(pma) also functions as an efficient interface layer, giving device performances very similar to those of analogous devices using NPD as the interface layer. Stability tests have been carried out for Co(ppz)(3)/NPD/Alq(3) and Co(ppy)(3)/NPD/Alq(3) devices. While fac-Co(ppy)(3) gave stable OLEDs, the fac-Co(ppz)(3)-based devices had very short lifetimes. On the basis of the experimental results of chemical oxidation of fac-Co(ppz)(3), the major cause for the fast decay of the fac-Co(ppz)(3) device is proposed to be the decomposition of fac-Co(ppz)(3)(+) in the HTL layer during the device operation.     

基于吡嗪空穴传输层的合成及在p-i-n型钙钛矿太阳能电池中的应用

钙钛矿太阳能电池由于具有高的光电转换效率,简单的溶液加工工艺,较低的成本等优势因而拥有广阔的应用前景。有机小分子空穴传输层材料在钙钛矿太阳能电池中扮演着极其重要的角色。在本工作中,我们设计和合成了基于吡嗪为分子中心核,三苯胺为分枝的X型空穴传输层材料PT-TPA。与Si-OMeTPA对比,吡嗪的引入不仅不会影响其结晶性,并且能够改善其电荷转移特性和分子中心共平面性,从而显著提升了PT-TPA的空穴迁移率。在非掺杂的情况之下,基于PT-TPA空穴传输层的p-i-n型钙钛矿太阳能电池展现出17.52%的光电转换效率,与相同条件下基于Si-OMeTPA空穴传输层的器件相比,效率提高了近15%。     

Halogen Vacancies Enable Ligand‐Assisted Self‐Assembly of Perovskite Quantum Dots into Nanowires

Interest has been growing in defects of halide perovskites in view of their intimate connection with key material optoelectronic properties. In perovskite quantum dots (PQDs), the influence of defects is even more apparent than in their bulk counterparts. By combining experiment and theory, we report herein a halide‐vacancy‐driven, ligand‐directed self‐assembly process of CsPbBr₃ PQDs. With the assistance of oleic acid and didodecyldimethylammonium sulfide, surface‐Br‐vacancy‐rich CsPbBr₃ PQDs self‐assemble into nanowires (NWs) that are 20–60 nm in width and several millimeters in length. The NWs exhibit a sharp photoluminescence profile (≈18 nm full‐width at‐half‐maximum) that peaks at 525 nm. Our findings provide insight into the defect‐correlated dynamics of PQDs and defect‐assisted fabrication of perovskite materials and devices.