Vacuum Sublimation Research Articles

Numerical Simulation and Experimental Analysis of Mare’s Milk Sublimation Drying

This study presents a combined numerical and experimental analysis of heat and mass transfer in mare’s milk during vacuum sublimation drying, which is a process essential for producing high-quality powdered products. The numerical model was developed using two-dimensional simulations and validated against experimental data obtained for varying sample thicknesses (3 mm, 5 mm, and 7 mm). Results demonstrated a strong agreement between the model and experimental temperature data, with a coefficient of determination (R2) of 95% during the sublimation process. The findings revealed that thinner samples (3 mm) exhibited a 20% faster drying rate than thicker samples (7 mm), highlighting the critical role of sample thickness in sublimation dynamics. Additionally, the effects of heat flux distribution and mass loss due to sublimation were analyzed to understand the drying dynamics. This study highlights the importance of optimizing process parameters such as chamber pressure, shelf temperature, and sample thickness to enhance drying efficiency and reduce processing time. The findings provide valuable insights for scaling vacuum sublimation drying of mare’s milk for industrial applications.

Fabrication of Porous TiO2 with Aligned Pores Using Tert-Butyl Alcohol Based Freeze Casting

The effect of freezing conditions on the pore structure of porous TiO2 fabricated using a freeze casting process with tert-butyl alcohol slurry was investigated. The raw powder was heat treated to manufacture a porous body with stable shape by suppressing volume change induced by the phase transformation of TiO2 powder. The XRD analysis result indicated that the anatase phase fraction in the raw powder could be converted to 98.6% rutile phase by heating it at 800°C for 30 min. Porous TiO2 ceramics with unidirectionally aligned pore channels were prepared by freezing tert-butyl alcohol slurry containing 10 vol% TiO2 powder under different freezing temperatures of -20, -30 and -40°C, respectively. After removing the frozen tert-butyl alcohol by sublimation in vacuum, the green samples were sintered at 1100°C for 4 h in air. The porous body contains directional pores with a size of approximately 30 µm, and a hexagonal pore shape corresponding to the crystal structure of tert-butyl alcohol was observed in the cross-section of the pores. Small pores were observed at the bottom part of the porous body near the Cu plate where the solidification heat was released, but relatively large pores were present at the upper part. Both microstructure observation and pore size distribution indicated that the pore size and the strut thickness increased significantly with increasing freezing temperature. The change in pore characteristics was explained as being mainly due to the difference in the solidification behavior of the slurry and the rearrangement of the solid powder.

Efficient Organic Light-Emitting Diodes Obtained by Introducing Gadolinium (Gd) Complexes Based on Pyrazolone Derivative Ligands as Hole Trappers.

The utilization of lanthanide (Ln) complexes in the realm of organic light-emitting diodes (OLEDs) has garnered extensive interest, particularly in their role as luminescent materials or electron trappers. A series of gadolinium (Gd) complexes with energy levels of high HOMO/LUMO and different triplet state energies were designed and synthesized by introducing substituents with different electronic effects onto the pyrazolone derivative ligands. Subsequently, these complexes were precisely purified by vacuum sublimation and codoped into the light-emitting layer (EML) of the OLEDs. This process was facilitated through the well-matched HOMO/LUMO levels and triplet energies among various functional materials. Consequently, the maximum external quantum efficiencies of blue, red, and green OLEDs were simultaneously enhanced with the ratios of 119%, 28%, and 71%, respectively. This improvement can be credited to the introduction of Gd(III) complex molecules within EMLs, which helps to capture excess holes and improve carriers' balance.

A Spontaneous Magnetic Moment in an Organic Radical: Synthesis and Characterization of Benzodioxepinyl-1,3,2-dithiazolyl.

The synthesis of the 1,3,2-dithiazolyl radical (1) derived from 3,4-dihydro-2H-1,5-benzodioxepine is described. Crystals of 1 were grown by vacuum sublimation and adopt the orthorhombic space group Pbca. DC SQUID magnetometry reveals Curie-Weiss behavior for T > 20 K (C = 0.376 emu K mol-1 and θ = +5.7 K) consistent with local ferromagnetic interactions. The presence of weaker antiferromagnetic interactions led to magnetic ordering as a canted antiferromagnet (TN = 3.8 K) with a small spontaneous moment (2.5 × 10-4 Nβ) and a small coercivity (ca. 8 Oe) at 2 K. Magnetic ordering was reflected in a field dependence of the magnetic susceptibility below 3.8 K and a peak in the low temperature heat capacity data. A canting angle of 0.08° was estimated from M vs H data.

Preliminary Removal of Mercury from Depleted Coal Sorbents by Thermal Vacuum Method with Associated Extraction of Precious Metal Composite

This paper presents the results of laboratory studies for the distillation of mercury from depleted coal sorbents produced in gold recovery factories using CIP technology. The mercury content in these materials is more than 1%. The developed technology was tested in a large-scale laboratory on a pilot vacuum sublimation electric furnace with the rheological movement of dispersed material. The use of this equipment makes it possible to demercurize various materials with fairly high moisture (up to 20%). It eliminates the use of an additional technological operation—drying the material in a vacuum drying oven. It has been shown that a high degree of mercury distillation is achieved (more than 99.8%) at 350–400 °C in the reaction space and residual pressure in the system of less than 1.33 kPa, with residual mercury content in the material of less than 0.001% (10 mg/kg), which complies with the European environmental standards. Mercury-free coal sorbents are sent for combustion for the additional extraction of precious metal composites. The proposed vacuum technology is characterized by its environmental safety because the process is performed in sealed equipment, eliminating toxic emissions of mercury vapor into the atmosphere. The proposed vacuum technology equipment is characterized by reliability and ease of use.

A versatile system for the growth of porphyrin films via electrospray and molecular sublimation in vacuum and their multi-technique characterization.

We present a system for the growth of molecular films in vacuum that exhibits high versatility with respect to the choice of molecular species. These can be either evaporated from powders or injected from solutions using an electrospray system, making it possible to handle particularly large and/or fragile molecules in a controlled environment. The apparatus is equipped with a reflectance anisotropy spectroscopy system for the in situ characterization of the optical response of the films and can be directly connected to a photoelectron spectrometer without breaking the vacuum. The system is conceived for the study and characterization of porphyrin films. Here, to showcase the range of possible analyses allowed by the experimental setup and test the operation of the system, novel results are provided on electrospray deposition on highly oriented pyrolytic graphite of Zn tetraphenyl porphyrins and Zn proto porphyrins, the latter featuring fragile side groups that make deposition from solution more attractive. In situ characterization is complemented by ex situ atomic force microscopy. Thanks to this multi-technique approach, changes in the film morphology and spectroscopic response are detected and directly related to the choice of the molecular moiety and growth method.

Scanning Probe Microscopy Characterization of Biomolecules enabled by Mass-Selective, Soft-landing Electrospray Ion Beam Deposition.

Scanning probe microscopy (SPM), in particular at low temperature (LT) under ultra-high vacuum (UHV) conditions, offers the possibility of real-space imaging with resolution reaching the atomic level. However, its potential for the analysis of complex biological molecules has been hampered by requirements imposed by sample preparation. Transferring molecules onto surfaces in UHV is typically accomplished by thermal sublimation in vacuum. This approach however is limited by the thermal stability of the molecules, i. e. not possible for biological molecules with low vapour pressure. Bypassing this limitation, electrospray ionisation offers an alternative method to transfer molecules from solution to the gas-phase as intact molecular ions. In soft-landing electrospray ion beam deposition (ESIBD), these molecular ions are subsequently mass-selected and gently landed on surfaces which permits large and thermally fragile molecules to be analyzed by LT-UHV SPM. In this concept, we discuss how ESIBD+SPM prepares samples of complex biological molecules at a surface, offering controls of the molecular structural integrity, three-dimensional shape, and purity. These achievements unlock the analytical potential of SPM which is showcased by imaging proteins, peptides, DNA, glycans, and conjugates of these molecules, revealing details of their connectivity, conformation, and interaction that could not be accessed by any other technique.

Tetrafluorosubstituted titanyl phthalocyanines: Structure of single crystals and phase transition in thin films

In this work, tetrafluorinated titanyl phthalocyanines with F-substituents in both peripheral (TiOPcF4-p) and non-peripheral (TiOPcF4-np) positions were synthesized and characterized by the methods of elemental analysis, IR and electronic absorption spectroscopies. The influence of the position of F-substituents on the structure of TiOPcF4-p and TiOPcF4-np single crystals and thin films grown by vacuum sublimation was studied. TiOPcF4-p crystallizes in the I4/m space group and its molecules form uniform stacks along the tetragonal axis. Introduction of F-substituents to non-peripheral positions leads to the change of the crystal structure: TiOPcF4-np crystallizes in the P-1 space group and its molecules are packed into 2D layers. Both phthalocyanines form oriented polycrystalline films when deposited by thermal sublimation in vacuum, but their phase composition is different from that of single crystals. The effect of post-deposition annealing of TiOPcF4-p and TiOPcF4-np films on their phase composition, morphology, optical absorption and Raman spectra, as well as conductivity was revealed. It was shown that a phase transition, which led to the appearance of an additional band in the near-IR region in the optical absorption spectrum, was observed in TiOPcF4-p films when heated, whereas no phase transition was observed in TiOPcF4-np films.

Organic Semiconductor Devices Fabricated with Recycled Tetra Pak®-Based Electrodes and para-Quinone Methides

This work presents the synthesis of para-quinone methides (p-QMs), which were deposited as films using the high vacuum sublimation technique after being chemically characterized. The p-QMs films were characterized morphologically and structurally using scanning electron microscopy, atomic force microscopy, and X-ray diffraction. In addition, their optical behavior was studied by means of ultraviolet–visible spectroscopy, and the optical gaps obtained were in the range of 2.21–2.71 eV for indirect transitions, indicating the semiconductor behavior of the p-QMs. The above was verified through the manufacture and evaluation of the electrical behavior of rigid semiconductor devices, in which fluorine-doped tin oxide-coated glass slides (FTO) were used as an anode and substrate. Finally, as an original, ecological, and low-cost application, the FTO was replaced by substrates and anodes made from recycled Tetra Pak®, generating flexible semiconductor devices. Although the electrical current transported depends on the type of p-QMs, the substituent in its structure, and the morphology, the kinds of substrate and anode also influence the type of electrical behavior of the device. This current–voltage study demonstrates that p-QM2 with 4-Cl-Ph as a radical, p-QM3 with 4-Et2N-Ph as a radical, and p-QM6 with 5-(1,3-benzodioxol) as a radical can be used in optoelectronics as semiconductor films.

Investigations on MoS2 plasma by infra-red pulsed laser irradiation in high vacuum

MoS2 targets were irradiated by infra-red (IR) pulsed laser in a high vacuum to determine hot plasma parameters, atomic, molecular and ion emission, and angular and charge state distributions. In this way, pulsed laser deposition (PLD) of thin films on graphene oxide substrates was also realized. An Nd:YAG laser, operating at the 1064 nm wavelength with a 5 ns pulse duration and up to a 1 J pulse energy, in a single pulse or at a 10 Hz repetition rate, was employed. Ablation yield was measured as a function of the laser fluence. Plasma was characterized using different analysis techniques, such as time-of-flight measurements, quadrupole mass spectrometry and fast CCD visible imaging. The so-produced films were characterized by composition, thickness, roughness, wetting ability, and morphology. When compared to the MoS2 targets, they show a slight decrease of S with respect to Mo, due to higher ablation yield, low fusion temperature and high sublimation in vacuum. The pulsed IR laser deposited MoS x (with 1 < x < 2) films are uniform, with a thickness of about 130 nm, a roughness of about 50 nm and a higher wettability than the MoS2 targets. Some potential applications of the pulsed IR laser-deposited MoS x films are also presented and discussed.

Laser desorption mass spectrometry of rubrene and photodissociation of its cation

Laser desorption mass spectrometry was employed to study rubrene using three different sample preparation methods. Pressed-pellet and films drop-cast from solution were investigated with a laser-desorption time-of-flight spectrometer. Jet-cooled rubrene cations were produced in a supersonic molecular beam by laser desorption from a film-coated metal rod and detected with time-of-flight mass spectrometry. The films for this process were produced by vacuum sublimation of powder samples. The mass spectra from each of these samples contained the parent molecular ion and fragments resulting from phenyl ring elimination - a pattern similar to that produced by electron impact ionization. The amount of fragmentation varied with sample preparation and desorption laser wavelength. The rubrene cation was mass selected and studied with UV laser photodissociation at 355 nm. The resulting fragmentation mass spectrum indicated the loss of one or two phenyl groups, but no more than this. Computational studies of the ion energetics were used to investigate the stable fragment ion structures and understand the energetics of the dissociation process.

Separation of arsenic and antimony: A comprehensive theoretical and experimental study

Arsenic is commonly used in alloy materials and the semiconductor industry, and has promising applications. Arsenic and antimony have similar physicochemical properties, and their binding and separation mechanisms are unknown, thereby limiting the purification and preparation of arsenic. This study, from a microscopic perspective, reveals that arsenic and antimony covalently interact in alloys through a combination of thermodynamic analysis and molecular dynamics simulations. In addition, antimony as arsenic-antimony clusters enters the gas phase, and the diffusion coefficients of the clusters are in the order of As4>As3Sb > As2Sb2>AsSb3. A green and efficient vacuum sublimation-graded condensation process for arsenic purification is proposed based on the different diffusion coefficients to obtain the optimal process parameters. The coalescence of arsenic on a condenser was normally distributed. The removal rate of antimony in the most concentrated area of the condensate was 91.37% under the optimal conditions of 748 K, 60 min, and 10 Pa. Thus, the proposed method effectively solves the challenging problem of separating arsenic and antimony, and the study results provide theoretical support for purifying arsenic via vacuum sublimation.

Low-temperature influence on the properties and efficiency of thin-film perovskite solar cells fabricated by the PVco-D technique

The study discussed in this publication aimed to develop a perovskite solar cell adapted to operating conditions at reduced temperature and pressure and less than 1 μm thick. The physical vapor co-deposition technique was proposed and successfully used to create a solar cell structure with a thin layer of hybrid perovskite as an energy-collecting material. A comprehensive analysis of methylammonium lead iodide behavior in a wide temperature range from 10 K to 320 K was carried out to implement this project. The initial phase included assessing the degradation of the perovskite material layer after cooling to the temperature of liquid helium and then re-heating it to room temperature. Then, using spectroscopic techniques, the characteristics of the layers' optical and electrical properties were determined. The obtained results allowed the design of the complete structure of a thin-film perovskite cell, which was made using only the vacuum sublimation process. Simulations using the SCAPS-1D program and experimental results showed high agreement and allowed for obtaining an efficiency of approximately 18.5 % in the interested temperature range. Perovskite solar cell stability tests over six months confirmed the positive impact of the proposed technique for depositing the complete cell structure on its temporal stability. The research results are optimistic for the applications of perovskite cells in space.

Removal of Antimony from Industrial Crude Arsenic by Vacuum Sublimation: Combination of Thermodynamics and Ab Initio Molecular Dynamics

Thermodynamic theory was employed in this study to investigate the feasibility of separating antimony (Sb) from crude arsenic (As) using vacuum sublimation. Ab initio molecular dynamics simulations are used to calculate the structure, stability, and diffusion properties of AsmSbn (m + n ≤ 6) clusters. As4, As3Sb, As2Sb2, and AsSb3 are the possible clusters in this thermodynamic calculation, and the molecular dynamics results confirmed their structural stability and stabilization in the gas phase. As4 had the largest diffusion coefficients, which is the reason it separates from the Sb-containing clusters (As3Sb, As2Sb2, and AsSb3) during gas-phase diffusion and condensation processes. The experimental results show that As vapor was transformed from crystalline to amorphous with increasing subcooling, and the Sb-containing clusters that enter the gas phase were mainly condensed and deposited at the proximal end of the heating zone. Not considering the volatilization rate, the removal rate of Sb in products can reach 99.35% by increasing the condensation disk and expanding the condensation zone; thus, experiments confirmed that industrial crude arsenic can realize deep Sb removal after vacuum sublimation.

Sublimed fine-grained dysprosium: Significant magnetocaloric effect

As is known, rare-earth metals (REMs) are promising magnetocaloric materials. The magnitude of the magnetocaloric effect (MCE) of REMs significantly depends on their purity. This paper presents results of studies of the magnetic and magnetocaloric properties of sublimed dysprosium, prepared in the course of the present study, with an emphasis on its impurity and structure perfection. The comprehensive analysis of the chemical composition of sublimed dysprosium, which was performed for the first time by atom probe tomography, showed that the metal corresponds to high-purity rare-earth metals (3 N+). The MCE effect was studied using direct measurements of the adiabatic temperature change (ΔTad) in pulsed (up to 50 T) and steady (up to 14 T) magnetic fields. The studies of the MCE of polycrystalline sublimed Dy by direct method showed that the high ΔTad value for sublimed Dy are comparable with those obtained for single-crystal Dy in magnetic fields up to 5 T. The vacuum sublimation, which is more economical and technologically advanced in contrast to single crystal growing, can be used to create magnetocaloric REM-based materials with high MCE values.

Nitro Indole Derivatives as Novel Dual-Polarity Matrices for MALDI Mass Spectrometry and Imaging with Broad Applications.

A new matrix framework is presented in this study for the improved ionization efficiency of complex mixtures by matrix-assisted laser desorption ionization (MALDI) mass spectrometry/imaging. Five nitro indole (NI) derivatives [3-methyl-4-nitro-1H-indole (3,4-MNI), 3-methyl-6-nitro-1H-indole (3,6-MNI), 2,3-dimethyl-4-nitro-1H-indole (2,3,4-DMNI), 2,3-dimethyl-6-nitro-1H-indole (2,3,6-DMNI), and 4-nitro-1H-indole (4-NI)] were synthesized and shown to produce both positive and negative ions with a broad class of analytes as MALDI matrices. NI matrices were compared to several common matrices, such as 2,5-dihydroxybenzoic acid (DHB), alpha-cyano-4-hydroxylcinnamic acid (CHCA), sinapinic acid (SA), 1,5-diaminonaphthelene (1,5-DAN), and 9-aminoacridine (9-AA), for the analysis of lipid, peptide, protein, glycan, and perfluorooctanesulfonic acid (PFOS) compounds. 3,4-MNI demonstrated the best performance among the NI matrices. This matrix resulted in reduced ion suppression and better detection sensitivity for complex mixtures, for example, egg lipids/milk proteins/PFOS in tap water, while 2,3,6-DMNI was the best matrix for blueberry tissue imaging. Several important aspects of this work are reported: (1) dual-polarity ion production with NI matrices and complex mixtures; (2) quantitative analysis of PFOS with a LOQ of 0.5 ppb in tap water and 0.05 ppb in MQ water (without solid phase extraction enrichment), with accuracy and precision within 5%; (3) MALDI imaging with 2,3,6-DMNI as a matrix for plant metabolite/lipid identification with ionization enhancement in the negative ion mode m/z 600-900 region; and (4) development of a thin film deposition under/above tissue method for MALDI imaging with a vacuum sublimation matrix on a high-vacuum MALDI instrument.

STRUCTURAL DIVERSITY OF OCTA- AND HEXADECAFLUORINATED TIN (II) AND TIN (IV) PHTHALOCYANINES

In this work crystal structures of octa- and hexadecafluoro-substituted tin(II) and tin(IV) phthalocyanines are shown. Complexes were obtained by fusing of fluorinated phthalonitriles with SnCl2 (Method 1) and refluxing the initial reagents in 1-chloronaphthalene (Method 2). In the case of octafluorosubstituted tin complexes it has been shown that during synthesis by the Method 1, Sn(II)PcF8 complexes are formed. At the same time, during the synthesis by the Method 2, Sn(IV)Cl2PcF8 complexes are obtained. It was demonstrated that not only the synthesis method but also the number of fluorine substituents affects the composition and structure of the obtained complexes. Unlike octasubstituted derivatives, only tin(IV) complexes are formed during the synthesis of hexadecafluorosubstituted phthalocyanines using both methods. Thus, when fusing tetrafluorophthalonitrile with SnCl2, halogen atoms are exchanged and a mixture of monomeric SnF2(PcF15Cl) and dimeric Sn2F3(PcF15Cl)2 complexes is formed. The synthesis in solution leads to the formation of SnCl2PcF16, which crystallizes together with 1-chloronapthalene solvate molecules. The effect of heating and vacuum sublimation on the transformation of Sn(IV) phthalocyanines is also studied.

Sublimation-based wafer-scale monolayer WS2 formation via self-limited thinning of few-layer WS2.

Atomically-thin monolayer WS2 is a promising channel material for next-generation Moore's nanoelectronics owing to its high theoretical room temperature electron mobility and immunity to short channel effect. The high photoluminescence (PL) quantum yield of the monolayer WS2 also makes it highly promising for future high-performance optoelectronics. However, the difficulty in strictly growing monolayer WS2, due to its non-self-limiting growth mechanism, may hinder its industrial development because of the uncontrollable growth kinetics in attaining the high uniformity in thickness and property on the wafer-scale. In this study, we report a scalable process to achieve a 4 inch wafer-scale fully-covered strictly monolayer WS2 by applying the in situ self-limited thinning of multilayer WS2 formed by sulfurization of WOx films. Through a pulsed supply of sulfur precursor vapor under a continuous H2 flow, the self-limited thinning process can effectively trim down the overgrown multilayer WS2 to the monolayer limit without damaging the remaining bottom WS2 monolayer. Density functional theory (DFT) calculations reveal that the self-limited thinning arises from the thermodynamic instability of the WS2 top layers as opposed to a stable bottom monolayer WS2 on sapphire above a vacuum sublimation temperature of WS2. The self-limited thinning approach overcomes the intrinsic limitation of conventional vapor-based growth methods in preventing the 2nd layer WS2 domain nucleation/growth. It also offers additional advantages, such as scalability, simplicity, and possibility for batch processing, thus opening up a new avenue to develop a manufacturing-viable growth technology for the preparation of a strictly-monolayer WS2 on the wafer-scale.

Structure of four vat dyes and of violanthrene

The structures of four industrially valuable vat dyes are solved for the first time: 1,1′-diethyl-[3,3′-bidibenzo[cd,g]indazole]-6,6′(1H,1′H)-dione (Vat Red 13, Cibanone Red 6B, Carbanthrene Red G 2B, Ahcovat Rubine R), 16,17-dimethoxyviolanthrone (Vat Green 1, Caledon Jade Green, Jade Green Base, Indanthren Brilliant Green B), pyranthrone (Vat Orange 9, Ahcovat Golden Orange G, Benzadone Gold Orange G, Pigment Orange 40), 2,8-diphenylanthra(2,1-d:6,5-d')bisthiazole-6,12-dione (Vat Yellow 2, Anthra Yellow, Tyrian Yellow A-GC) and violanthrene. Violanthrene was obtained by reduction of 16,17-dimethoxyviolanthrone with sodium metal in ethanol. The single crystals were grown by vacuum sublimation and examined with a synchrotron radiation source. The structures of all the four vat dyes represent a stacking motif, whereas violanthrene molecules form sandwiches of two molecules. The interplanar distance between the molecules in the stacks (sandwiches) is 3.35–3.48 Å which is typical of polycyclic aromatic compounds.

AIEgen configuration transition and aggregation enable dual prompt emission for single‐component nondoped white OLEDs

AbstractThe dual emission (DE) feature in materials holds great potential to revolutionize the development of one‐component system white organic light‐emitting diodes (WOLEDs). However, the reported DE materials remain scarce owing to the formidable challenge of breaking Kasha's rule and managing the intricate energy/charge transfer processes. Herein, we have introduced a groundbreaking DE AIEgen, 2CzAn‐TPE, which possesses a simple structure and undergoes Z‐to‐E isomerization and exhibits yellow and red fluorescence powders for pre‐ and post‐sublimation, respectively. With relatively lower potential energy, Z‐conformation ((Z)‐1,2‐diphenyl‐1,2‐bis(4‐(10‐(9‐phenyl‐9H‐carbazol‐3‐yl)anthracen‐9‐yl)phenyl)ethene) of 2CzAn‐TPE can be readily transformed into E‐conformation ((E)‐1,2‐diphenyl‐1,2‐bis(4‐(10‐(9‐phenyl‐9H‐carbazol‐3‐yl)anthracen‐9‐yl)phenyl)ethene) via vacuum sublimation. The utilization of X‐ray diffraction and grazing‐incidence‐wide‐angle X‐ray scattering techniques confirms the structural transformation, while the crystallographic analysis reveals the establishment of numerous intermolecular CH···π interactions between the tetraphenylethene (TPE) moiety and both the anthracene and carbazole units. This allows a densely packed molecular arrangement, thereby offering propitious conditions for excimer generation in the E‐conformation aggregated state. By utilizing the sublimated 2CzAn‐TPE as an emitter, a nondoped one‐component WOLED was prepared, exhibiting an exceptionally high external quantum efficiency (EQE) of 5.0%, which represents one of the highest performances among all one‐component WOLEDs. This research introduces a novel, simple, and efficient approach to realize highly efficient one‐molecule WOLEDs.