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Two piloted premixed CH $ _4 $ 4 /air jet flames with extreme turbulence are modelled using the Flamelet-Generated Manifold (FGM) method in the context of Large Eddy Simulation (LES). Free-propagating and reactant-to-product laminar flames are adopted to build unstrained and strained chemical databases, respectively. Detailed comparison of the LES-FGM results using the unstrained/strained databases is conducted which is validated against the direct numerical simulation results. The results show that whether including straining effects in the database will not influence the modelling of temperature and major species (e.g. CH $ _4 $ 4 , O $ _2 $ 2 and CO $ _2 $ 2 ), but using a strained database is essential for predictions of intermediate minor species (e.g. H $ _2 $ 2 , CH $ _2 $ 2 O, OH and CO). The main reason is that the major species and temperature are almost insensitive to the straining due to the supportive effects from the pilot flame, which also tentatively explains why the unstrained database can be employed to model these strong turbulent flames. In contrast, the intermediate minor species are more prone to the straining, so that using a strained database is crucial. The preferential diffusion effects on the species and temperature predictions are examined to be negligible. It is proposed that adding extra transport equations for these minor species also leads to satisfactory predictions if using an unstrained database, which helps to include the straining effects on the minor species. This study is expected to be significant in high-fidelity simulations of strong turbulent flames using flamelet-tabulated combustion models. [ABSTRACT FROM AUTHOR]

Overcoming exciton quenching and improving electroluminescence (EL) performances continue to pose persistent challenges in the development of efficient deep blue thermally activated delayed fluorescence (TADF) emitters. Herein, an asymmetric multi‐donors strategy is employed that provides the potential of establishing multiple radiative transition channels for fluorescence emission and reverse intersystem crossing (RISC), while allowing flexible modulation of packing modes in single‐crystal state and optimization of morphology in films by modifying the substitution site of the donor units. As a result, intermolecular π–π interactions are effectively alleviated and a very smooth surface with a reduced defect density is simultaneously achieved, which can significantly reduce the density of triplet excitons, accelerate the charge transfer rate, and enhance carrier injection efficiency. Consequently, a super‐high photoluminescence quantum yield (PLQY) of 99% and fast kRISC of 1.1 × 105 s−1 are concurrently achieved for the proof‐of‐concept emitter 3,4‐Cz‐SF‐SFAC. The corresponding deep‐blue organic light‐emitting diode (OLED) demonstrates an exceptional external quantum efficiency (EQE) of 31.1%, accompanied by an emission peak at 457 nm, one of the preeminent TADF materials within the deep blue region, ranking among the most efficient OLEDs with an EL spectra below 460 nm on record. [ABSTRACT FROM AUTHOR]

Multi‐resonance (MR) based organoboron emitters exhibiting high‐efficiency narrowband thermally activated delayed fluorescence (TADF) have become a critical material component for constructing high‐performance organic light‐emitting diodes (OLEDs) with high color purity and high color gamut. However, most of the MR‐TADF devices suffer from severe efficiency roll‐off at high current density due to the relatively large singlet–triplet splitting energy, long excited state lifetime, and slow reverse intersystem crossing rate (kRISC). Herein, by utilizing a sulfur atom‐fused donor unit, 7H‐benzo[4,5]thieno[2,3‐b]carbazole, an organic boron emitter (BTC‐BNCz) capable of high efficiency and low efficiency roll‐off narrowband TADF emission is developed. Benefitting from the heavy atom effect of the sulfur atom, kRISC up to 1.6 × 105 s−1 is achieved, which could greatly reduce the undesired quenching effect. Consequently, the OLED using BTC‐BNCz as dopant exhibits high external quantum efficiency (EQE) of 27.0% with full width at half maximum (FWHM) of 35 nm. Moreover, by utilizing a TADF material with a high horizontal dipole ratio as assistant host, outstanding device performance is achieved with a maximum EQE of 35.2% and FWHM of 37 nm, featuring slow efficiency roll‐off. [ABSTRACT FROM AUTHOR]

Solely through‐space charge transfer (TSCT)‐type thermally activated delayed fluorescent (TADF) emitters exhibit low radiative decay rates (krs$k_{\rm{r}}^{\rm{s}}$), while solely through‐bond charge transfer (TBCT) type TADF emitters generally suffer from low reverse intersystem crossing (RISC) rates (kRISC). Here, PhCzSpiroS‐TRZ with versatile spiro‐heterocyclic architecture and an extra donor of 9‐phenyl‐9H‐carbazole are developed as emitter and ideal host for TADF‐ and TADF‐sensitized fluorescence (TSF) organic light‐emitting diodes (OLEDs) in detail. Abandoning solely TSCT or TBCT process, PhCzSpiroS‐TRZ with multiple charge transfer characteristic exhibits photoluminescence quantum yield of 96.3% and krs$k_{\rm{r}}^{\rm{s}}$ of 2.2 × 107 s−1, which is considerably higher among all the reported TSCT‐TADF molecules. Noticeably, state‐of‐the‐art blue OLEDs using PhCzSpiroS‐TRZ as emitter and sensitizer show maximum external quantum efficiencies (EQEs) of 33.6% and 32.8%, ranking among TADF materials for achieving EQEs >30% in both TADF‐ and TSF‐OLEDs. [ABSTRACT FROM AUTHOR]

Pearson's chi-squared test is widely used to test the goodness of fit between categorical data and a given discrete distribution function. When the number of sets of the categorical data, say k, is a fixed integer, Pearson's chi-squared test statistic converges in distribution to a chi-squared distribution with k−1 degrees of freedom when the sample size n goes to infinity. In real applications, the number k often changes with n and may be even much larger than n. By using the martingale techniques, we prove that Pearson's chi-squared test statistic converges to the normal under quite general conditions. We also propose a new test statistic which is more powerful than chi-squared test statistic based on our simulation study. A real application to lottery data is provided to illustrate our methodology. [ABSTRACT FROM AUTHOR]

Metal halide perovskites have drawn substantial interest in optoelectronic devices in the past decade. Perovskite/electrode contacts are crucial for constructing high‐performance charge‐transporting‐layer‐free perovskite devices, such as solar cells, field‐effect transistors, artificial synapses, memories, etc. Many studies have evidenced that the perovskite layer can directly contact the electrodes, showing abundant physicochemical, electronic, and photoelectric properties in charge‐transporting‐layer‐free perovskite devices. Meanwhile, for perovskite/metal contacts, some critical interfacial physical and chemical processes are reported, including band bending, interface dipoles, metal halogenation, and perovskite decomposition induced by metal electrodes. Thus, a systematic summary of the role of metal halide perovskite/electrode contacts on device performance is essential. This review summarizes and discusses charge carrier dynamics, electronic band engineering, electrode corrosion, electrochemical metallization and dissolution, perovskite decomposition, and interface engineering in perovskite/electrode contacts‐based electronic devices for a comprehensive understanding of the contacts. The physicochemical, electronic, and morphological properties of various perovskite/electrode contacts, as well as relevant engineering techniques, are presented. Finally, the current challenges are analyzed, and appropriate recommendations are put forward. It can be expected that further research will lead to significant breakthroughs in their application and promote reforms and innovations in future solid‐state physics and materials science. [ABSTRACT FROM AUTHOR]

Research on asphalt fatigue and self-healing performance can more accurately model the damage and self-healing evolution principles in practical applications. In order to analyze the rationality of evaluation indexes based on rheology to evaluate the self-healing properties of TPU modified asphalt, a dynamic shear rheometer (DSR) was used in this study to perform time, temperature, and frequency sweep tests of TPU modified asphalt for analyzing the fatigue self-healing properties of TPU modified asphalt over a broader range of temperatures and loading frequencies. This method can improve the accuracy of the fatigue failure determination criteria of TPU modified asphalt and clarify the material performance parameters of TPU asphalt modifiers. The results showed that the increase in hard segment content (C h) and isocyanate radical index (r) can effectively alleviate the decrease in shear deformation resistance of modified asphalt caused by the increase in N (load repetition). N f50 (the number of loads when the normalized modulus drops to 0.5) is more suitable to evaluate the fatigue life of TPU modified asphalt compared with N p20 (the number of loads when the DER - N curve is offset by 20% deviation from the linear undamaged line) and N 2 (the number of load times corresponding to the intersection point of the tangent line of the DER – N fitted curve and the undamaged line). The degree of self-healing will also increase with the increase in C h and r. Besides, the higher the healing temperature and the healing time, the longer the fatigue life. The effects of the self-healing evaluation index (HI) on the self-healing index of TPU modified asphalt were as follows: healing temperature > healing time > soft segment > C h > r > degree of damage > degree of aging > deg r ee of self-healing. • The effects of different segments of polyurethanes on the fatigue self-healing ability of modified asphalt were analyzed. • A viscoelastic master curve for comprehensive analysis of wide temperature and wide frequency bands was established. • The versatility and accuracy of N f50 as an evaluation index for the fatigue life of TPU modified asphalt were determined. • Through comparative experiments, the appropriate synthesis parameters and dosage of TPU asphalt modifier were determined. • The effects of factors on the self-healing index HI were analyzed and sorted by gray correlation coefficient. [ABSTRACT FROM AUTHOR]

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With the progress of sci-tech, the interdisciplinary and comprehensive development, and various advanced sci-tech gradually integrated into the field of sports, it has become possible to study how to reasonably prevent sports injuries, minimize the risk of sports injuries, and maintain the best physical condition of retired athletes. Due to the long-term high-load exercise of retired athletes during their sports career, athletes' physical functions have been damaged to varying degrees, resulting in more injuries. According to the characteristics that many factors need to be considered in the prediction of retired athletes' injuries, this paper puts forward an improved self-organizing neural network (SOM) method to predict retired athletes' injuries. In this paper, an early warning analysis model of retired athletes' susceptibility to injury based on SOM is proposed, which screens the state of retired athletes' physical function variables in each stage, considers athletes' physical function data whose standard deviation is higher than the limit specification of susceptibility to injury as susceptible injury data, quickly judges all vulnerable injury data, and completes the high-speed early warning analysis of retired athletes' susceptibility to injury. [ABSTRACT FROM AUTHOR]

Excessive reactive oxygen species (ROS) generated during cerebral ischemic reperfusion (CIRI) are crucial for subsequent tissue damage. However, despite the potential benefits of antioxidants reported in clinical applications, few have proven effective in treating CIRI, particularly in the elderly. Epicatechin (EC) is a catechol flavonoid monomer derived from natural tea plants. Multiple phenolic hydroxyl groups give it strong antioxidant properties, which can not only degrade ROS through chemical reactions between hydroxyl and ROS but also enhance the activity of antioxidant enzymes in cells, and it is easy to penetrate the blood–brain barrier. But its antagonistic effect on age‐related CIRI and potential medicinal value are still unknown. Nuclear factor erythroid 2‐related factor 2 (Nrf2) is the most important transcription factor regulating the expression of antioxidant proteins in the body. This study first compared the pathological differences of the Nrf2 system in CIRI between 2‐month‐old and 12‐month‐old Sprague–Dawley (SD) rats. Subsequently, EC was administered to 12‐month‐old rat models of middle cerebral artery occlusion and reperfusion (MCAO/R) and senescent SH‐SY5Y cell models subjected to oxygen glucose deprivation/reoxygenation (OGD/R). EC treatment improved cerebral morphology and function; increased p‐Nrf2, heme oxygenase‐1 (HO‐1), superoxide dismutase (SOD), and glutathione (GSH) expression; reduced infarct volume; and neuronal apoptosis in senescent rats. Moreover, EC enhanced cellular activity and the expression of p‐Nrf2, HO‐1, and quinone oxidoreductase‐1 (NQO‐1) while decreasing ROS and malondialdehyde (MDA) levels and mitigating apoptosis in senescent SH‐SY5Y cells. These effects were reversed upon si‐Nrf2. In sum, we confirm that EC exerts neuroprotective effects by upregulating Nrf2/ARE and reducing oxidative stress, suggesting that EC may be a promising drug for the treatment of senile cerebral apoplexy. This study also provides a scientific basis for the development and selection of new drugs for ischemic stroke in elderly patients. [ABSTRACT FROM AUTHOR]

• Numerical analysis of the performance of a new fishtail-type stirrer. • PIV experiments validate the correctness of the model. • Compared to the RT impellers, fishtail impeller reduce power consumption by 16.4 %. • Compared to the RT impeller, fishtail impellers are effective in reducing mixing times and increasing mixing efficiency. • The fishtail impeller increases the pumping flow by 13.5 % and the pumping efficiency by 27.66 % compared to the RT impeller. In this study, a new fishtail impeller was introduced to improve the mixing of fluids in the stirred tank. The validity of the numerical model was first demonstrated by PIV experiments. Secondly, the CFD technique was used to analyze and predict the flow field characteristics in the stirred tank. Also, the effect of blade inclination on the mixing effect is analyzed. Finally, a comparative Analysis with the whale tail impeller is carried out to demonstrate the superiority of this research work. The results show that The results of the study showed that the power number of the fishtail impeller was reduced by 16.4 % compared to the RT impeller. The pumping efficiency of the fishtail impeller was increased by 25.52 %. The results also show that increasing the blade inclination increases the turbulent kinetic energy in the stirred tank. Comparative analysis with the whale-tail impeller reveals that the power number of the fish-tail impeller is reduced by 17.2 % and the pumping efficiency is increased by 19.97 %. [Display omitted] [ABSTRACT FROM AUTHOR]

Electrode materials with two-dimensional (2-D) structures have attracted tremendous attention because they can exhibit many excellent electrochemical and chemical properties. Herein, we present a simple and general self-template-etched solution route to fabricate 2-D γ-manganese sulfide (γ-MnS) nanoplates using Mn3[Fe(CN)6]2 as a sacrificial template and Mn source. Detailed analysis and experimental results indicate that the ethylene glycol/H2O-assisted hydrothermal system and the unique metal frameworks are vitally important for the formation, structure, and morphology of plate-shaped γ-MnS during the sulfidation process. By controlling the growth and etching process, a possible growth mechanism was proposed to interpret the formation of 2D γ-MnS nanoplates. As a promising anode material for pseudocapacitors, the γ-MnS nanoplate sample not only delivers a good specific capacity of 378 F g−1 at 0.2 A g−1 and high rate capability in neutral solution, but it also displays an excellent stable performance, with only about 10% loss after continuous charge–discharge cycling for 4000 cycles at 1.0 A g−1. The method appears to be a new way for using the sulfuration transformation matrix to obtain other two-dimensional transition metal compounds. [ABSTRACT FROM AUTHOR]

Aims: To report experience of perioperative nursing of tracheal silicon stent implantation in infants. Methods: Retrospective analysis on the cases of tracheal silicon stent implantation in infants in our hospital. Results and Conclusions: Since middle of 2014, totally four tracheal silicon stent implantation were performed in our center. Of them, one case was recurrent tracheoesophageal fistula and the other three cases were traheomalacia. Parent’s psychological support, infants’ nutrition support and airway care were key responsibility for a nurse before implantation. During the procedure of stent implantation, it was responsible for a nurse to closely monitor the infants and to support operator. After the implantation, airway care and prevention of intra-airway bacterial colonization were important to avoid complications. [ABSTRACT FROM AUTHOR]

Aims: To report experience of perioperative nursing of tracheal silicon stent implantation in infants.Methods: Retrospective analysis on the cases of tracheal silicon stent implantation in infants in our hospital.Results and Conclusions: Since middle of 2014, totally four tracheal silicon stent implantation were performed in our center. Of them, one case was recurrent tracheoesophageal fistula and the other three cases were traheomalacia. Parent's psychological support, infants' nutrition support and airway care were key responsibility for a nurse before implantation. During the procedure of stent implantation, it was responsible for a nurse to closely monitor the infants and to support operator. After the implantation, airway care and prevention of intra-airway bacterial colonization were important to avoid complications. [ABSTRACT FROM AUTHOR]

Two novel bipolar isomers, namely 3,5-bis(3-(9 H -carbazol-9-yl)phenyl)isonicotinonitrile ( m -DCzPyCN), and 3,5-bis(9-phenyl-9 H -carbazol-3-yl)isonicotinonitrile (3-DCzPyCN), are designed and synthesized by selecting cyanopyridine as n-type unit and N -phenylcarbazole as p-type unit. Two peripheral carbazoles are conjugated through their C-3 atom with the central cyanopyridine in 3-DCzPyCN but are indirectly linked through the N-9 atom via meta -phenylene bridges in m -DCzPyCN. The linking strategy had significant effect on the physical properties of the isomers. The single-carrier device study reveals that 3-DCzPyCN has much better positive and negative charge balancing ability than m -DCzPyCN. The 3-DCzPyCN hosted green phosphorescent organic light-emitting diode exhibits superior performance over m -DCzPyCN, with the maximum current efficiency of 84.1 cd A −1 and external quantum efficiencies of 24.2% and low efficiency roll-off. At an extremely high brightness of 10000 cd m −2 , the efficiency still remained at 78.4 cd A −1 , which corresponds to a roll-off of 6.7% from the maximum value. Even at an ultra-high brightness of 100000 cd m −2 , the efficiency is reduced by 47.0%. The superior performance of 3-DCzPyCN is ascribed to its remarkable charge balancing capability, which is the combined result of the cyanopyridine as n-type unit and the conjugated linking strategy between p- and n-type moieties. [ABSTRACT FROM AUTHOR]

Consider the product of m independent n × n random matrices from the spherical ensemble for m ≥ 1 . The spectral radius is defined as the maximum absolute value of the n eigenvalues of the product matrix. When m = 1 , the limiting distribution for the spectral radii has been obtained by Jiang and Qi (2017). In this paper, we investigate the limiting distributions for the spectral radii in general. When m is a fixed integer, we show that the spectral radii converge weakly to distributions of functions of independent Gamma random variables. When m = m n tends to infinity as n goes to infinity, we show that the logarithmic spectral radii have a normal limit. [ABSTRACT FROM AUTHOR]

• Hosts with TADF, conventional fluorescence and RTP characters are developed. • Exciton utilization efficiency is improved by the host with TADF character. • An EQE of 36.1% was achieved for sky blue OLED with DspiroAc-TRZ as emitter. • An EQE of 34.0% was achieved for the sensitized device with v -DABNA dopant. Spiral donor units have attracted extensive research focuses in designing highly emissive thermally activated delayed fluorescence (TADF) emitters. Herein, to reveal the significance of spiral donor units for constructing highly efficient host materials, several spiral donor-based host materials are developed. With the incorporation of spiral donor, increased intermolecular distance is achieved to reduce the concentration quenching effect of dopant. Moreover, the high triplet energy level of spiral donor can provide an additional energy transfer channel to further improve the device performance. Noteworthy, by connecting spiral donors or conventional carbazole unit with different electron-withdrawing units phenoxathiine 10,10-dioxide (PX) or phenoxathiine (PA), these hosts are given different photophysical properties of TADF, room-temperature phosphorescence (RTP) and conventional fluorescence (CF). The strong electron-withdrawing ability of PX is beneficial to the TADF character of spiral donor-based molecules, while the weak electron-withdrawing ability of PA is beneficial to the RTP property. Consequently, the blue OLEDs with DspiroAc-TRZ as a dopant emitter based on the hosts with TADF characters exhibit higher performance than those with RTP and CF properties, and excellent external quantum efficiency (EQE) of 36.1 % and current efficiency of 84.6 cd/A are achieved in a simple device structure. Furthermore, peak EQEs of 34.0 % and 33.0 % are achieved, when DspiroS-PX and DspiroS-PA hosted DspiroAc-TRZ are used to sensitize blue multi-resonance TADF emitter v -DABNA. Our work may shed new light on designing highly efficient host materials for TADF emitters. [ABSTRACT FROM AUTHOR]

For bootstrap sample sums resulting from a sequence of random variables { X n , n ≥ 1 } , a very general central limit theorem is established. The random variables { X n , n ≥ 1 } do not need to be independent or identically distributed or to be of any particular dependence structure. Furthermore, no conditions, including moment conditions, are imposed in general on the marginal distributions of the { X n , n ≥ 1 } . As a special case of the main result, a result of Liu (1988) concerning independent but non-identically distributed { X n , n ≥ 1 } is extended to a larger class of parent sequences. A version of the main result is also presented wherein the bootstrap sample sums have random bootstrap sample sizes. [ABSTRACT FROM AUTHOR]

In order to investigate the convergence rate of the asymptotic normality for the estimator of the conditional mode function for the left-truncation model, we derive a Berry–Esseen type bound of the estimator when the lifetime observations with multivariate covariates form a stationary α-mixing sequence. The finite sample performance of the estimator of the conditional mode function is explored through simulations. [ABSTRACT FROM PUBLISHER]

A cubic Mn 0.6 Fe 0.4 S solid solution material has been synthesized using a scalable in situ sulfuration treatment of Prussian-blue analogs (PBAs), and its phase formation process and Li-storage mechanism were investigated. Increased treatment temperature and time encourage a phase transformation from hexagonal Fe 7 S 8 to cubic FeS 2 during the sulfuration process, which results in the formation of a solid solution between cubic FeS 2 and cubic MnS. The resulting Mn 0.6 Fe 0.4 S solid solution electrode exhibits high initial coulombic efficiency, excellent rate performance, and superior cycling stability (520 mA h g−1 after 1000 cycles at 1.0 A g–1). Ex-situ X-ray diffractometry and electro-kinetics tests show that the doping-induced structural phase transition in Mn 0.6 Fe 0.4 S solid solution creates a favorable electronic structure and ensures rapid charge transfer kinetics during the lithiation/delithiation process, simultaneously achieving high energy conversion efficiency and a long lifespan. [Display omitted] • Cubic Mn 0.6 Fe 0.4 S solid solution as anode material is successfully synthesized. • The phase transition from α-MnS to metastable β-MnS could be induced in the charge process. • The improvement in electrochemical performance is attributed to the doping-induced structural phase transition in Mn0.6Fe0.4S. [ABSTRACT FROM AUTHOR]

Let 0 < p < 2 and 1 ≤ q < ∞. Let {Xn; n ≥ 1} be a sequence of independent copies of a real-valued random variable X and set Sn = X1 + · · ·+Xn, n ≥ 1. We say X satisfies the (p, q)-type strong law of large numbers (and write X ∈ SLLN(p, q)) if ... < ∞ almost surely. This paper is devoted to a characterization of X ∈ SLLN(p, q). By applying results obtained from the new versions of the classical Lévy, Ottaviani, and Hoffmann-Jørgensen (1974) inequalities proved by Li and Rosalsky (2013) and by using techniques developed by Hechner (2009) and Hechner and Heinkel (2010), we obtain sets of necessary and sufficient conditions for X ∈ SLLN(p, q) for the six cases: 1 ≤ q < p < 2, 1 < p = q < 2, 1 < p < 2 and q > p, q = p = 1, p = 1 < q, and 0 < p < 1 ≤ q. The necessary and sufficient conditions for X ∈ SLLN(p, 1) have been discovered by Li, Qi, and Rosalsky (2011). Versions of the above results in a Banach space setting are also given. [ABSTRACT FROM AUTHOR]

This paper deals with the conditional quantile estimation based on left-truncated and right-censored data. Assuming that the observations with multivariate covariates form a stationary α-mixing sequence, the authors derive the strong convergence with rate, strong representation as well as asymptotic normality of the conditional quantile estimator. Also, a Berry-Esseen-type bound for the estimator is established. In addition, the finite sample behavior of the estimator is investigated via simulations. [ABSTRACT FROM AUTHOR]

Letbe a sequence of independent and identically distributedB-valued random variables, and set. Let,andq>0, and putWe strengthen the convergence rate for the Kolmogorov–Marcinkiewicz–Zygmund strong law of large numbers in Banach space, by showing that, if and only ifand [ABSTRACT FROM PUBLISHER]

Sulfone‐embedded heterocyclics are of great interest in organic light‐emitting diodes (OLEDs), however, exploring highly efficient narrowband emitters based on sulfone‐embedded heterocyclics remains challenging. Herein, five emitters with different sulfur valence state and molecular rigidity, namely tP, tCPD, 2tCPD, tPD and tPT, are thoroughly analysed. With restricted twisting of flexible peripheral phenyl by strengthening molecular rigidity, molecular emission spectra can be enormously narrowed. Further, introducing the sulfone group with bending vibration in low‐frequency region that suppresses high‐frequency vibration, sharp narrow full‐widths at half‐maximum of 28 and 25 nm are achieved for 2tCPD and tPD, respectively. Maximum external quantum efficiencies of 22.0 % and 27.1 % are successfully realized for 2tCPD‐ and tPD‐based OLED devices. These results offer a novel design strategy for constructing narrowband emitters by introducing sulfone group into a rigid molecular framework. [ABSTRACT FROM AUTHOR]

Sulfone‐embedded heterocyclics are of great interest in organic light‐emitting diodes (OLEDs), however, exploring highly efficient narrowband emitters based on sulfone‐embedded heterocyclics remains challenging. Herein, five emitters with different sulfur valence state and molecular rigidity, namely tP, tCPD, 2tCPD, tPD and tPT, are thoroughly analysed. With restricted twisting of flexible peripheral phenyl by strengthening molecular rigidity, molecular emission spectra can be enormously narrowed. Further, introducing the sulfone group with bending vibration in low‐frequency region that suppresses high‐frequency vibration, sharp narrow full‐widths at half‐maximum of 28 and 25 nm are achieved for 2tCPD and tPD, respectively. Maximum external quantum efficiencies of 22.0 % and 27.1 % are successfully realized for 2tCPD‐ and tPD‐based OLED devices. These results offer a novel design strategy for constructing narrowband emitters by introducing sulfone group into a rigid molecular framework. [ABSTRACT FROM AUTHOR]

Gastric cancer is one of the most common cancers worldwide, particularly in China, with over half a million new cases and over 400 thousand deaths in 2022. Zolbetuximab, a first-in-class investigational monoclonal antibody (mAb) targeting tumor-associated antigen CLDN18.2 which is highly expressed on gastric cancer cells, was recently reported to meet the primary endpoint in Phase III trial as first-line treatment in CLDN18.2 positive and HER2-negative gastric cancers. In the present study, we developed a humanized bispecific antibody (bsAb) CLDN18.2/4-1BB named PM1032. PM1032 activates immune cells via CLDN18.2 mediated crosslinking of 4-1BB, a potent stimulator of T/NK cells. It induced strong immunological memory in multiple tumor-bearing animal models, indicating significant potential as an effective treatment for CLDN18.2 positive cancers such as gastric cancer. Since liver and gastrointestinal (GI) related toxicities were reported in 4-1BB and CLDN18.2 targeting programs during the clinical development, respectively, extensive pharmacokinetics (PK) and safety profile characterization of PM1032 was performed in rhesus monkeys. PM1032 had a half-life comparable to a conventional IgG1 mAb, and serum drug concentration increased in a dose-dependent pattern. Furthermore, PM1032 was generally well tolerated, with no significant abnormalities observed in toxicity studies, including the liver and stomach. In summary, PM1032 demonstrated good PK and an exceptional safety profile in rhesus monkeys supporting further investigation in clinical studies. [ABSTRACT FROM AUTHOR]

The steam-diluted oxyfuel combustion of the hydrogen-enriched fuels is promising to attain zero-emission in the energy system. One critical challenge for this technology is the flame stabilization, which was examined in this work mainly through the flame structure analysis. The burner adopted three swirlers to enhance the mixing, which leads to V-shaped diffusion-like flames. Starting from the purely hydrogen fuel, the CH 4 addition effects with fractions of 20% and 40% were studied. Meanwhile, combustion with different equivalence ratios were also compared, when the volume flowrate ratio of the O 2 and steam was kept constantly at 1:4. For these diffusion-like flames, the reaction zone was obtained using the OH-PLIF. Then, the flame structure statistics, such as the number and area of the broken reaction zone and its thickness, were all examined. Results show that the fuel properties and steam flowrate intensively affect the flame stabilization. With increased CH 4 addition in the hydrogen fuel, the reaction zone tends to be broken seriously. This is characterized by frequently appeared small reaction zone fragments, along with largely decreased reaction zone area. With a larger stream flow rate, the local flame extinction is also increased obviously and the flame branches can be completely distinguished due to the intensive straining effects. The extinction upstream is observed to promote an enveloped reaction zone downstream, due to the unburned fuel leakage. It is found that the mean reaction zone thickness is overall close, which varies from 1 to 2 mm, but can be modified by different factors. An analogical comparison of the reaction thickness to the laminar counter-flame thickness reveals that the CH 4 addition and flow straining can decrease the reaction zone thickness, but the accompanied turbulence effects can broaden it to at least about 1.2 times. These results are beneficial to attain a stable ultra-clean combustion utilizing hydrogen-based flexible fuels. [Display omitted] • Steam-diluted swirling CH 4 /H 2 /O 2 flames are studied. • The flame is a diffusional type and can be unstable. • Extinction is increased with either CH 4 addition or high steam flowrate. • Extinction and fuel leakage lead to enveloped reaction zone downstream. • The reaction zone thickness can be broadened by turbulence. [ABSTRACT FROM AUTHOR]

Device model simulation is one of the primary tools for modeling thin film solar cells from organic materials to organic–inorganic perovskite materials. By directly connecting the current density–voltage (J–V) curves to the underlying device physics, it is helpful in revealing the working mechanism of the heatedly discussed organic–inorganic hybrid perovskite solar cells. Some distinctive optoelectronic features need more phenomenological models and accurate simulations. Herein, the application of the device model method in the simulation of organic and organic–inorganic perovskite solar cells is reviewed. To this end, the ways of the device model are elucidated by discussing the metal–insulator–metal picture and the equations describing the physics. Next, the simulations on J–V curves of organic solar cells are given in the presence of the space charge, interface, charge injection, traps, or exciton. In the perovskite section, the effects of trap states, direct band recombination, surface recombination, and ion migration on the device performance are systematically discussed from the perspective of the device model simulation. Suggestions for designing perovskite devices with better performance are also given. [ABSTRACT FROM AUTHOR]

• Zn 2 Ti 3 O 8 /ZnTiO 3 and Zn 2 TiO 4 /R-TiO 2 heterostructures were prepared through a two-step chemical route. • The heterostructure catalysts showed improved photocatalytic activities for CO 2 reduction with H 2 O. • Zn 2 Ti 3 O 8 /ZnTiO 3 and Zn 2 TiO 4 /R-TiO 2 heterojunctions favor the separation and transfer of charge carriers. • The band gap structures and the working mechanisms of Zn 2 Ti 3 O 8 /ZnTiO 3 and Zn 2 TiO 4 /R-TiO 2 heterojuntions were proposed. Photocatalytic reduction of CO 2 with H 2 O on photocatalysts to produce fuels presents great potential to simultaneously address energy and environmental issues. Herein, zinc titanate-based heterostructured nanohybrids including Zn 2 Ti 3 O 8 /ZnTiO 3 and Zn 2 TiO 4 /R-TiO 2 were designed and prepared through a two-step chemical route. When used as photocatalyst for converting CO 2 with H 2 O under UV-light irradiation, the zinc titanate-based heterostructured nanohybrids show high photocatalytic performance, with CH 4 and CO yields significantly higher than those obtained with Zn 2 Ti 3 O 8 , Zn 2 TiO 4 , and rutile TiO 2 as the photocatalysts. The existence of heterojunctions in the nanohybrids was demonstrated by experimental results, and electrochemical impedance spectra also reveal a favorable zinc titanate-based heterostructure. Moreover, based on theoretical calculations, the observed reduced band gap further revealed the effective light-absorption of the heterostructured nanohybrids in CO 2 reduction. It is thus concluded that the synergistic effect of the heterostructure promotes charge separation and fast electron transport, resulting in its enhanced photocatalytic performance in CO 2 reduction. [ABSTRACT FROM AUTHOR]

Mixed halide perovskites are widely investigated as emitters for efficient light‐emitting diodes owing to their excellent optoelectronic properties. Compared with red and green emissions, encouraging progress in efficiency for blue emission has only been achieved in sky‐blue region. A high Cl/Br ratio is indispensable to achieve deep‐blue emission, which often leads to pronounced halogen migration in perovskite light‐emitting diodes (PeLEDs) and thus diminished efficacy. To avoid the negative effects of excessive chloride necessary to achieve deep‐blue emission, alloyed perovskite quantum dotes (QDs) passivated by dual‐functional guanidine sulfamate are synthesized, where S═O of sulfamate coordinates with Pb, and guanidine can form N‐H‐X (Cl/Br) with halogen ions to complete passivation. As a result, deep‐blue emission is achieved for the alloyed perovskite QDs. Owing to the suppressed defects and the reduced surface electrostatic potential of the perovskite QDs film, the carrier recombination region in the PeLEDs is regulated. Finally, deep‐blue PeLEDs with a spectrally stable electroluminescence peak at 458 nm, peak external quantum efficiency of 3.65% and maximum brightness of 223 cd m−2 are realized. [ABSTRACT FROM AUTHOR]

Sulfone group plays a pivotal role in narrowing emission spectra, while, precise modification with sulfone group for carbonyl‐based narrowband emitters that maintain high color purity remains challenging. Herein, a comprehensive exploration of the function of the sulfone group is performed with various sulfur valences and positions fused into traditional carbonyl‐based narrowband emission unit QAO, namely SpiroS‐QAO, SpiroSO2‐QAO, SpiroO‐QAO, and SpiroOSO2‐QAO. A rigid molecular skeleton with a spiro structure as an intramolecular lock enables the four emitters to exhibit narrowband emissions. After full oxidization of sulfur, the emission band of SpiroSO2‐QAO is further narrowed, with full width at half maximum of 32 nm, compared to that of 43 nm for sulfane‐decorated SpiroS‐QAO, which is attributed to the suppressed C─S bond‐length variation by the introduction of sulfone group. Nearly identical spectra of SpiroO‐QAO and SpiroOSO2‐QAO suggest that the sulfone group should be directly linked to the emission core to maximize its function. Maximum external quantum efficiencies of 30.8%, 30.3%, and 29.2% are achieved for SpiroO‐QAO, SpiroOSO2‐QAO, and SpiroS‐QAO‐based sensitized organic light‐emitting diodes with highly efficient thermally activated delayed fluorescence assistant host. These results offer a comprehensive understanding of the sulfone group embedded into the narrowband emission core with respect to the narrowing emission band. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbon (PAH) compounds are prospective materials for highly efficient narrowband organic light‐emitting diodes. Specifically, boron‐nitrogen doped PAHs exhibit multiple resonance (MR) effect toward thermally activated delayed fluorescence (TADF) and narrow full width at half‐maximum (FWHM). Currently, the molecular design strategy for bathochromic‐shifted narrowband MR‐TADF emitters is a hotspot and challenging puzzle. Herein, a carbonyl is fused in the boron‐nitrogen doped PAH for constructing a boron/nitrogen/carbonyl MR‐TADF emitter. Benefiting from the carbonyl, the developed emitter exhibits enhanced intramolecular charge transfer and decreased reorganization energy, which displays bathochromic‐shifted narrowband emission pertinently. As a consequence, the proof‐of‐concept compound TCZBAO achieves an emission peak at 522 nm and narrow FWHM of 39 nm, while the carbonyl‐free TCZBAC exhibits an emission peak at 502 nm and FWHM of 46 nm. Maximum external quantum efficiencies of 36.1 % and 32.4 % are realized for the devices based on TCZBAO and TCZBAC, respectively, indicating the guiding significance of the proposed design strategy for developing bathochromic‐shifted narrowband MR‐TADF emitters. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) have become the forefront and hot pot of new photovoltaic technology due to their high efficiency, low cost, and easy preparation. Understanding the microstructure characteristics of the perovskite films is one of the key factors to further improve the efficiency and stability. The characteristics of grains based on the self‐developed perovskite film morphology analysis software GrainD are studied in this article. Important perovskite film information such as the average radius of grains, the distribution pattern of grain size, the area of grain contact, and the total number of grains are obtained. The results show that the grain size distribution of the polycrystalline perovskite film follows the lognormal distribution. According to statistical probability theory and grain growth theory, the multiplication effect of multiple random factors of film growth is proposed as the reason for the lognormal distribution. This study provides an important method for analyzing the perovskite films and gives clues about the crystallization kinetics. [ABSTRACT FROM AUTHOR]

For an array of rowwise pairwise negative quadrant dependent, mean 0 random variables, Chandra, Li, and Rosalsky provided conditions under which weighted averages converge in L1 to 0. The Chandra, Li, and Rosalsky result is extended to Lr convergence (1≤r<2) and is shown to hold under weaker conditions by applying a mean convergence result of Sung and an inequality of Adler, Rosalsky, and Taylor. [ABSTRACT FROM AUTHOR]

Developing high‐efficiency electrocatalysts for hydrogen evolution reaction (HER) is vitally important in electrochemical water splitting technology. Herein, ultra‐small Ni‐doped CuCo2S4 nanoparticles (NCCS NPs) are easily achieved in a single step by a facile hydrothermal method. The investigations, using powder X‐ray diffraction, X‐ray photoelectron spectroscopy, scanning electron microscopy, and TEM, reveal that the as‐prepared NCCS products are composed of a large number of uniform nanoparticles with sizes ranging from 20 to 50 nm. Triethanolamine is of vital importance for the formation of the NCCS NPs during the sulfidation process. As a promising electrocatalyst for HER, the NCCS NPs not only display a lower overpotential at 10 mA cm−2 current density than that of bare CuCo2S4 nanoparticles (CCS NPs), but also show better long‐term durability than CCS NPs during the galvanostatic electrolysis. Furthermore, Ni doping for NCCS NPs are proved to play a particular important role in the HER process. This finding provides a strategy in compositional tuning of mixed polymetallic sulfides catalysts for electrochemical hydrogen evolution. Ultra‐small Ni‐doped CuCo2S4 nanoparticles (NCCS NPs) are easily achieved in one step by hydrothermal method. The formation mechanism of NCCS NPs during the sulfidation process is proposed. Ni doping for NCCS NPs is proved to play a critical role in the catalysis of Hydrogen Evolution Reaction (HER). This finding provides a strategy in compositional tuning of polymetallic sulfides for HER. [ABSTRACT FROM AUTHOR]

For arrays of rowwise pairwise negative quadrant dependent random variables, conditions are provided under which weighted averages converge in mean to 0 thereby extending a result of Chandra, and conditions are also provided under which normed and centered row sums converge in mean to 0. These results are new even if the random variables in each row of the array are independent. Examples are provided showing (i) that the results can fail if the rowwise pairwise negative quadrant dependent hypotheses are dispensed with, and (ii) that almost sure convergence does not necessarily hold. [ABSTRACT FROM AUTHOR]

Incorporating pyridyl uniquely from its 2-position onto 10-site of acridone ring generated intramolecular hydrogen bond in a group of acridone-carbazole hybrid thermally activated delayed fluorescence emitters, which universally pulled down non-radiative transition rates by three orders and elevated reverse intersystem crossing rates by two orders, and thus boosted PLQYs to almost unity and EQEs of OLEDs to 30+%, representing the state-of-the-art efficiencies of deep-blue TICT-TADF materials and devices with CIEy≤0.10. [Display omitted] • Intramolecular-hydrogen-bond boosts performance of deep blue TADF emitters. • H-bond reduces k nr by 3 orders and increases k RISC by 2 orders. • PLQYs≈100 %, k RISC s ≥ 105 s−1 and horizontal orientation ratios ≥90 % are obtained. • Deep blue OLEDs exhibit record-high EQEs of 31–33 % with CIE y of 0.09–0.12. A group of D-A-D type thermally activated delayed fluorescence (TADF) emitters were developed with 10-(pyridin-2-yl)acridin-9(10 H)-one as acceptor and substituted carbazoles as donors. The design was focused on incorporating pyridyl to the 10-site nitrogen atom of acridin-9(10 H)-one ring, which improved the reverse intersystem crossing rate constant k RISC from 103 s−1 to 105 s−1. More importantly, the linkage of pyridyl uniquely from its 2-position to acridin-9(10 H)-one ring induced intramolecular hydrogen bond, which suppressed nonradiative transition rates by three to four orders of magnitude and universally increased the photoluminescence quantum yields from 54 % to nearly 100 %. In combination with the intrinsic high horizontal orientation ratios over 90 % of acridin-9(10 H)-one based molecules, such pyridyl decoration boosted the external quantum efficiencies of simple-structure deep blue organic light-emitting diodes to 31–33 % with CIE x of 0.15 and CIE y of 0.09 ∼ 0.12, being double of that for hydrogen-bond-free parent emitter and representing the state-of-the-art efficiencies for the deep blue twisted intramolecular charge transfer type TADF materials with CIEy ≤ 0.10 so far. These TADF emitters are comparable with the prevailing multiresonance blue emitters in terms of distinctive efficiencies, but advantageous in much facile syntheses. [ABSTRACT FROM AUTHOR]

Using a screen‐printing techniques is thought to be a good candidate for simplified, cost‐effective, reliable, and scalable fabrication of fully printed perovskite solar cells (PSCs) for industrialization. Nevertheless, the screen‐printing of perovskite film has not been realized until recently. This group finished the work using ionic liquid methylamine acetate (MAAc) as pure solvent. However, the space‐confining effect during the perovskite crystallization in mesoporous impeded the escape of bottom MAAc molecules, which leads to the poor crystalline quality of the screen‐printed film. In this work, ionic liquid methylamine propionate (MAPa) with stronger coordination is introduced as a co‐solvent to promote the escape of MAAc molecules by forming the solvent volatilization channels in a confined mesoporous structure, which results in the complete MAAc volatilization and high filling degree of perovskite crystals inside the mesoporous structure. Also, MAPa promotes the vertical growth of perovskite crystals and coordinates with unbonded Pb2+ on the perovskite surface, leading to efficient charge transport and interfacial band alignment of the screen‐printed film. Finally, fully screen‐printed PSCs yields a champion power conversion efficiency (PCE) of ≈17%, which is the record value for fully screen‐printed PSCs. Moreover, the unencapsulated device shows robust operational stability that maintains >85.3% of initial PCE (25%RH and 25 °C) under continuous illumination at the maximum power point after 250 h. [ABSTRACT FROM AUTHOR]

Doping‐free organic light‐emitting diodes (OLEDs) are beneficial to reduce manufacturing costs for mass production, which, however, are limited by the ubiquitous aggregation‐caused quenching (ACQ) effect, especially for thermally activated delayed fluorescence (TADF) emitters with relatively long exciton lifetimes. Herein, two typical TADF emitters pACRS and pACRSO with different sulfur atom valence states are developed, where pACRS with a thioether unit exhibits suppressed intermolecular interaction, alleviated ACQ effect, and higher efficiency in a conventional doping‐free device, in contract to pACRSO with a sulfone unit. It is of interest that comparable efficiencies are achieved for both emitters in doping‐free OLEDs with an ultrathin emission layer (UEML), in which the emitter molecules are deposited onto the surface of the underlying organic layer of host material to form an ultrathin quasi‐host‐guest system with alleviated ACQ effect. Besides, the suppressed trap effect is the key to guarantee the efficiency of UEML‐OLEDs, while different intermolecular interactions of emitters that determine the optimized UEML thickness will affect the efficiency roll‐off. Furthermore, benefiting from the UEML structure, highly efficient doping‐free OLEDs are also successfully achieved for red TADF emitters with stronger intermolecular interactions. Such an UEML strategy meeting efficiency and cost demands holds great promise for doping‐free OLEDs. [ABSTRACT FROM AUTHOR]

Let X be an observable random variable with unknown distribution function F(x)=P(X≤x), −∞, and let θ=sup{r≥0:E|X|r<∞}. We call θ the power of moments of the random variable X. Let X1,X2,…,Xn be a random sample of size n drawn from F(⋅). In this paper we propose the following simple point estimator of θ and investigate its asymptotic properties: θˆn=lognlogmax1≤k≤n|Xk|, where logx=ln(e∨x), −∞. In particular, we show that θˆn→Pθif and only iflimx→∞xrP(|X|>x)=∞∀r>θ. This means that, under very reasonable conditions on F(⋅), θˆn is actually a consistent estimator of θ. [ABSTRACT FROM AUTHOR]

White organic light-emitting diodes (WOLEDs) based on all thermally activated delayed fluorescence (TADF) emitters are especially attractive due to the merits of high efficiency and low cost. Novel TADF emitters (TFM-QP and CN-QP) were developed by selecting 6-(trifluoromethyl)quinoxaline or 6-(cyano)quinoxaline as the electron acceptor and phenoxazine as the electron donor. Aggregation induced emission is detected. Small singlet and triplet energy splitting values of 0.03–0.04 eV and long fluorescence lifetimes of 1.6–5.0 μs confirm their TADF nature. The chromaticity of monochromic OLEDs with TFM-QP and CN-QP as doped emitters was adjustable from yellow to orange–red by varying the doping concentration, and the yellow OLEDs exhibit external quantum efficiencies (ηext) of 14.4% and 9.7% at a low doping level. Full-TADF WOLEDs were fabricated using TFM-QP or CN-QP in combination with the sky-blue TADF emitter DMAC-DPS. The single-emitting-layer doped warm-white OLED (CN-QP:DMAC-DPS) exhibits excellent performance with a low turn-on voltage of 2.8 V, a stable color rending index (CRI) of 72, and high efficiencies of 48.22 cd A−1, 50.47 lm W−1, and 20.16%, which should be the highest efficiency records ever reported for full-TADF warm-white OLEDs so far. The non-doped full-TADF WOLED with an emitting layer structure of DMAC-DPS/TFM-QP/DMAC-DPS achieves a high CRI of 86 and a moderate ηext of 8.7%. [ABSTRACT FROM AUTHOR]

High‐quality hosts are indispensable for simultaneously realizing stable, high efficiency, and low roll‐off blue solution‐processed organic light‐emitting diodes (OLEDs). Herein, three solution processable bipolar hosts with successively reduced triplet energies approaching the T1 state of thermally activated delayed fluorescence (TADF) emitter are developed and evaluated for high‐performance blue OLED devices. The smaller T1 energy gap between host and guest allows the quenching of long‐lived triplet excitons to reduce exciton concentration inside the device, and thus suppresses singlet‐triplet and triplet‐triplet annihilations. Triplet‐energy‐mediated hosts with high enough T1 and better charge balance in device facilitate high exciton utilization efficiency and uniform triplet exciton distribution among host and TADF guest. Benefited from these synergetic factors, a high maximum external quantum efficiency (EQEmax) of 20.8%, long operational lifetime (T50 of 398.3 h @ 500 cd m−2), and negligible efficiency roll‐off (EQE of 20.1% @ 1000 cd m−2) are achieved for bluish‐green TADF OLEDs. Additionally introducing a narrowband emission multiple‐resonance TADF material as terminal emitter to accelerate exciton dynamic and improve exciton utilization, a higher EQEmax of 23.1%, suppressed roll‐off and extended lifetime of 456.3 h are achieved for the sky‐blue sensitized OLEDs at the same brightness. [ABSTRACT FROM AUTHOR]

A simple and one-step solvothermal synthesis method has been developed to prepare two-dimensional (2-D) hydrohausmannite ((Mn 4-2x Mn x )Mn 8 O 16-x (OH) x ) nanoplates with radial length of 300 nm and thickness of about 25 nm in a binary ethanediamine/water solvent system. The formation mechanism of hydrohausmannite is suggested. As an anode material for electrochemical capacitors, the plate-shaped hydrohausmannite not only displays a high specific capacity (215 at 0.1 A g −1 ) and good rate capability, but also shows good stable performance along with 94% specific capacity retained after 3000 cycle tests. The method can be easily controlled and expected to be applicable for the large-scale preparation of the 2-D hydrohausmannite. [ABSTRACT FROM AUTHOR]

[Display omitted] • Coexistence of intra-CT and inter-CT processes is realized for DPA-XA-TRZ. • Dual CT processes can be simultaneously enhanced by planar molecular skeleton. • Organic light-emitting diodes with external quantum efficiency of 21.9% is realized. • Efficiency of 31.7% is realized by DPA-XA-TRZ sensitized device with DMAc-BN dopant. Intramolecular charge transfer (intra-CT) and intermolecular charge transfer (inter-CT) are two general molecular design strategies of thermally activated delayed fluorescence (TADF) materials for organic light-emitting diodes (OLEDs). Herein, a diphenylamine (DPA) donor and a 2,4-diphenyl-1,3,5-triazine (TRZ) acceptor are connected by two planar units, non-conjugated 9,9-dimethyl-9 H -xanthene (XA) and conjugated dibenzo[ b,d ]furan (FR), to give D-σ-A type emitter DPA-XA-TRZ and D-π-A type emitter DPA-FR-TRZ. Coexistence of intra- and inter-CT is found for DPA-XA-TRZ and is readily tuned by various doping concentrations owing to the non-conjugated linkage. In contrast, DPA-FR-TRZ shows a dominant intra-CT characteristic due to the strong molecular conjugation. The planar molecular skeleton of DPA-XA-TRZ could not only enhance intramolecular electronic coupling, but also reduce steric hindrance and shorten intermolecular distance to enhance inter-CT process. A maximum external quantum efficiency (EQE max) of 21.9 % is achieved for the OLED device based on DPA-XA-TRZ, which is 2.5 times higher than that of DPA-FR-TRZ (8.4 %). DPA-XA-TRZ can also be utilized as an assistant host to sensitize multiple resonance TADF emitter DMAc-BN, and an EQE max of 31.7 % is realized owing to its dual CT processes and high reverse intersystem crossing rate (k RISC), which is significantly superior to the conventional mCBP host and mCBP:PO-T2T exciplex cohost. [ABSTRACT FROM AUTHOR]

Organic–inorganic perovskite solar cells (PSCs) have achieved great attention due to their expressive power conversion efficiency (PCE) up to 25.7%. To improve the photovoltaic performance of PSCs, interface engineering between the perovskite and hole transport layer (HTL) is a widely used strategy. Following this concept, benzyl trimethyl ammonium chlorides (BTACls) are used to modify the wet chemical processed perovskite film in this work. The BTACl‐induced low dimensional perovskite is found to have a bilayer structure, which efficiently decreases the trap density and improves the energy level alignment at the perovskite/HTL interface. As a result, the BTACl‐modified PSCs show an improved PCE compared to the control devices. From device modeling, the reduced charge carrier recombination and promoted charge carrier transfer at the perovskite/HTL interface are the cause of the open‐circuit (Voc) and fill factor (FF) improvement, respectively. This study gives a deep understanding for surface modification of perovskite films from a perspective of the morphology and the function of enhancing photovoltaic performance. [ABSTRACT FROM AUTHOR]