Higher Binding Energy Research Articles

Investigation of the Chemical Changes from N-Doped Graphene and MOF to N-G/MOF Composites for the Enhancement of Electrocatalytic Properties

N-doped graphene (N-G) materials showed high potential as electrocatalysts for oxygen reduction reaction (ORR) in electrochemical energy systems and increasingly gaining ground as alternatives to the expensive and degradation-prone Platinum Group Metal (PGM)-based electrocatalysts. Numerous studies demonstrated that as N-G materials are integrated with Metal-Organic Frameworks (MOFs), the N-G/MOF composites exhibited higher electrocatalytic activities than the individual precursors; on several occasions, even higher than the PGM-based ones. In this essence, it is crucial to analyze and understand the chemical changes that occur through the integration of N-G and MOF, as these changes play key roles in enhancing electrocatalytic properties of the materials by introducing different electrochemically active sites. To investigate such chemical changes, we have synthesized an N-G/MOF composite by integrating an N-G with ZIF-8 (which is the most studied member of the MOF family) following a facile mechanochemical wet ball milling process. In the electrochemical characterization, the N-G/MOF composite performed better than N-G and ZIF-8 for ORR catalysis by generating a higher cathodic current density.Multiple samples of N-G, ZIF-8, and N-G/MOF composite were analyzed by X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy to detect the changes in elemental ratios, chemical bonds, and chemical functional groups from the precursors (N-G and ZIF-8) to the N-G/MOF composite. An increase in the elemental Nitrogen (N) ratio was observed in N-G/MOF compared to its precursors; which signifies an increased N-doping ratio in the material which is advantageous for ORR catalysis. The XPS C 1s spectra of N-G/MOF shifted to a higher binding energy (~1eV) compared to the precursors indicating an overall increase in the oxidation states of Carbon (C) atoms in the material which could facilitate oxygen molecules’ adsorption better on these sites at the beginning of ORR process. Comparing the analyzed XPS N 1s spectra revealed an increased relative ratio of the Pyridinic-N functional group in N-G/MOF, which also partly justifies the composite’s enhanced ORR electrocatalytic performance. FTIR analysis revealed interactions between methyl groups (-CH3) of ZIF-8 with oxygen functional groups (i.e. -OH) of N-G while forming the N-G/MOF composite. Besides, a transition from methyl groups (-CH3) to methylene group ( >CH2) was evident during the synthesis, increasing charge density near those C atoms of the N-G/MOF which can as well be advantageous for ORR electrocatalysis. The combined impact of these chemical alterations from N-G and ZIF-8 to N-G/MOF yielded a synergistic effect, elucidating its superior electrocatalytic properties. The findings of this experimental investigation provide insights into the chemical reasons for the enhancement of electrocatalytic properties of N-G/MOF composites; and hereby offer guidance to the design and optimization endeavors of novel catalysts with N-G and MOF materials for diverse electrochemical applications.

Cimicifugin, a broad-spectrum inhibitor of Theileria annulata and Plasmodium falciparum CDK7.

Cyclin-dependent kinase 7 is an attractive therapeutic target for the treatment of cancers, and a previous report suggested that Plasmodium falciparum CDK7 is a potential drug target for developing new anti-malarial drugs. In this study, we aimed to characterize and evaluate the drug target potential of Theileria annulata CDK7. Theileria annulata is responsible for tropical theileriosis, which induces a phenotype similar to cancerous cells like immortalization, hyperproliferation, and dissemination. Virtual screening of the MyriaScreen II library predicted 14 compounds with high binding energies to the ATP-binding pocket of TaCDK7. Three compounds (cimicifugin, ST092793, and ST026925) of these 14 compounds were non-cytotoxic to the uninfected bovine cells (BoMac cells). Cimicifugin treatment led to the activation of the extrinsic apoptosis pathway and induced autophagy in T. annulata-infected cells. Furthermore, cimicifugin also inhibited the growth of P. falciparum, indicating that it has both anti-theilerial and anti-malarial activities and that TaCDK7 and PfCDK7 are promising drug targets.

Identification of phytoestrogens as sirtuin inhibitor against breast cancer: Multitargeted approach

Despite progress in diagnosis and treatment strategies, breast cancer remains a primary risk to female health as indicated by second most cancer-deaths globally caused by this cancer. High risk mutation is linked to prognosis of breast cancer. Due to high resistance of breast cancer against current therapies, there is necessity of novel treatment strategies. Sirtuins are signaling proteins belonging to histone deacetylase class III family, known to control several cellular processes. Therefore, targeting sirtuins could be one of the approaches to treat breast cancer. Several plants synthesize phytoestrogens which exhibit structural and physiological similarities to estrogens and have been recognized to possess anticancer activity. In our study, we investigated several phytoestrogens for sirtuin inhibition by conducting molecular docking studies, and in-vitro studies against breast cancer cell lines. In molecular docking studies, we identified coumestrol possessing high binding energy with sirtuin proteins 1–3 as compared to other phytoestrogens. The molecular dynamic studies showed stable interaction of ligand and protein with higher affinity at sirtuin proteins 1–3 binding sites. In cell proliferation assay and colony formation assay using breast cancer cell lines (MCF-7 and MDAMB-231) coumestrol caused significant reduction in cell proliferation and number of colonies formed. Further, the flow cytometric analysis showed that coumestrol induces intracellular reactive oxygen species and the western blot analysis revealed reduction in the level of SIRT-1 expression in breast cancer cell lines. In conclusion, in-silico data and in-vitro studies suggest that the phytoestrogen coumestrol has sirtuin inhibitory activity against breast cancer.

Design, Synthesis, and Biological and in silico Evaluation of Novel Indazole-pyridine Hybrids for the Treatment of Breast Cancer.

The prevalence of breast cancer presents a substantial global health concern, underscoring the ongoing need for the development of inventive therapeutic remedies. In this investigation, an array of novel indazole-pyridine hybrids (5a-h) have been designed and synthesized to assess their potential as candidates for treating breast cancer. Subsequently, we have conducted biological evaluations to determine their cytotoxic effects on the human MCF-7 breast cancer cell line. Furthermore, in silico analysis was conducted to estimate the inhibition potential of the compounds against TrkA (Tropomyosin receptor kinase A), a specific molecular target associated with breast cancer, through molecular docking. In silico physicochemical and pharmacokinetic predictions were made to assess the compounds' drug-like properties. Compound 5a emerged as the most active compound among the others with GI50 < 10 μg/ml. Besides, compound 5a showed high binding energy (BE -10.7 kcal/mol) against TrkA and was stabilized within the TrkA binding pocket through hydrophobic, H-bonding, and van der Waals interactions. In silico physicochemical and pharmacokinetic prediction studies indicated that compound 5a obeyed both Lipinski's and Veber's rule and displayed a versatile pharmacokinetic profile, implying compound 5a to appear as a viable candidate and that it could be further refined to develop therapeutic agents for potentially treating breast cancer. This study offers a promising direction for the advancement of innovative breast cancer treatments, highlighting the effectiveness of indazole-pyridine hybrids as potential anticancer agents. Further optimization and preclinical development are necessary to advance these compounds to clinical trials.

Damage analysis caused by 60Co ions in functionally graded materials

Functionally graded composite/hybrid materials (FGCM/FGHCM) were produced by adding B4C, TiO2, and B4C+TiO2 ceramic materials at various ratios (0–50%) into the AA6082 matrix. The analysis of the damage caused by 60Co ions' (1.173–1.1332 MeV) on the material was examined using the SRIM/TRIM Monte Carlo simulation software. In the simulation, the following data regarding the atoms of the target materials were obtained: ion distribution, target ionization, total displacements, surface binding energy, lattice binding energy, and displacement energy. Among the studied four materials, the one with the highest ion range value was found to be AA6082 with 8550 Å. TiO2 was found to be the reinforcement material that reduced the ion range the most in the material. Due to its high binding energy, B4C reinforced AA6082+(0–50%) B4C FGCM was found to have the least vacancy with 4782/ion.

Comparative study on the antioxidant efficacy of Adinandra nitida extracts in inhibiting lipid oxidation in edible oils

Exploring natural antioxidants is essential to delay lipid oxidation. This study investigated the inhibitory effect of Adinandra nitida (AN) extract in six edible oils, compared to TP and TBHQ. Methods included extract preparation, bioactive compounds analysis, in vitro antioxidant activities by FRAP, DPPH, and ABTS assays, fatty acid composition detection, and POV determination. The results showed that AN was rich in total flavonoids, total phenols and had better iron ion reduction ability than TBHQ. In oleic and linoleic acid-rich oils, AN significantly delayed early-stage lipid oxidation, outperforming TP and TBHQ. In linolenic acid-rich oils, AN maintained a stable effect. Molecular docking studies revealed strong binding interactions between main compounds and fatty acids, with Camelliaside A in (7.83) showing higher binding energy to linolenic acid than TBHQ (7.64), supporting the antioxidant effects. These findings suggest AN as a promising natural alternative to synthetic antioxidants, enhancing oil stability and shelf life.

Pain healing potential of famous traditional fermented Rhododendron (Lali-Guras) beverages from Indo-Nepal Himalaya: In vitro and in silic o evaluation

Abstract This in vitro and in silico study was designed to validate acclaimed anti-inflammatory or pain-relieving properties of fermented ethnic beverages prepared from Rhododendron or Guras flowers in the Singalila ridge- the famous Rhododendron growing region of the Himalayas. Traditional beverages Guras wine and its distilled version Guras Raksi were considered in this study which were collected from Gairibas, a village situated in Indo-Nepal Singalila Ridge of the Himalayas. In vitro protein (albumin) denaturation inhibition assay was conducted to evaluate anti-inflammatory activity of the samples and later GC-MS analysis was carried out to identify anti-inflammatory compounds present in those beverages. From GC-MS results, eleven major metabolites such as 5-hydroxymethylfurfural; quinic acid; clionasterol; l-(+)-ascorbic acid, 2,6-dihexadecanoate; d-sorbitol; cis-cinnamic acid; tyrosol; lupeol; methyl commate A; 2-hydroxy-gamma-butyrolactone; and 1,3-propanediol, 2-(hydroxymethyl)- 2-nitro- were chosen for molecular docking with human cyclooxygenase-1 (hCOX-1), an important targets in the drug-design for nonsteroidal anti-inflammatory drugs. Among all query compounds, phytosterol- clionasterol and triterpenoid- lupeol and methyl commate A exhibited considerably high binding energy scores (&lt;-8 kcal/mol) even compared to anti-inflammatory drugs- acetaminophen and ibuprofen. Outcome of this research affirmed the potential of Gurasbased traditional drinks in the healing of different forms of high-altitudinal stress induced pain.

Computational study of phytochemical derived bioactive compounds of Vernonia amygdalina as a potential inhibitor of Topoisomerase IV in pneumonia

Several of the bacteria responsible for pneumonia had become resistant to available antibiotics. According to the WHO, the resistance of Klebsiella pneumonia to Ciprofloxacin is 79.4%, making infections such as pneumonia and several diseases more difficult, if not impossible to treat. The prevalence of antimicrobial resistance is a global problem and among the 10 top global health threats facing humanity. With the projection of 10 million deaths per year by 2050 due to bacterial infections associated with antibiotic resistance according to WHO, there is an urgent need to identify an alternative approach to curb the incessant antimicrobial resistance and a complementary approach is to employ the use of naturally occurring compounds with potent antibacterial activities. We employed structural bioinformatics and theoretical chemistry techniques via molecular docking, and pharmacokinetic study, to identify novel S. pneumoniae topoisomerase IV inhibitors. The stringent molecular docking identified Arg140, Arg81, Glu55, Pro84, Met83, and Asn51, as principal amino acid residues for topoisomerase IV ligand interactions. Ten of the bioactive compounds found in Vernonia amygdalina showed a higher binding energy when compared to the reference compound (Ciprofloxacin). The overall analysis of MD results and binding free energy calculations reveal that Luteolin and 7-O-methylwogonin displayed stable trajectories with acceptable RMSD values and sufficient high negative energies throughout the MD simulation run of 100ns. These identified bioactive compounds in this study can be taken further for in vitro and In vivo studies to examine their efficacy against Pneumonia.

Synthesis and characterizations of zinc oxide nanorods by cost effective aqueous hydrothermal technique for solid state lighting applications

Zinc oxide (ZnO) is recognized as the most promising and often utilized semiconducting material due to its exceptional physical, chemical, optical, and relatively low-cost production features, as well as its ecologically beneficial nature. ZnO is a prominent candidate owing to its wide band gap (3.37 eV at room temperature) as well as its high exciton binding energy (60 meV) for the next generation of ultraviolet and blue optoelectronic devices. This would be achieved through the development of hybrid heterostructured LED devices with low manufacturing costs by blending gallium nitride (GaN) with zinc oxide (ZnO), which serves as the most efficient opto-electronic device. Due to its high electron mobility, high transparency in the visible wavelength spectrum, and low work function, ZnO is also a highly investigated transparent conducting oxide thin film for several applications. Besides, their incredible optical capabilities, ZnO-based optical devices, such as light-emitting diodes (LEDs) and laser diodes (LDs), have drawn a great deal of interest. This reported research work demonstrates the growth of high-density, high-aspect-ratio ZnO nanorod (NR) arrays on p-type gallium nitride substrates employing low-cost facial aqueous hydrothermal syntheses with optimised growing conditions. Additionally, a top-down chemical etching technique is adapted for fabricating zinc oxide nanotubes. High-quality ZnO nanorods with high intensity that were a few microns long were found across the GaN substrate with FESEM analysis. The chemical composition of the grown nanorods is confirmed with EDAX analysis. The wurtzite crystalline structure and c-axis orientation of the grown ZnO NR-arrays were identified in X-ray diffraction studies. A Schimadzu UV–Vis–NIR spectrophotometer was used to record the optical curve, and the energy gap was determined to be 3.24 eV by plotting the Tauc curve. The good optical quality of the harvested nanorods is ensured by the narrow near-band-edge (NBE) emission at 384 nm and defect emission peaks detected through photoluminescence analyses. Grown specimens are also subjected to Raman spectrum analyses, and the obtained results are presented.

Turmeric-Black Cumin Essential Oils and Their Capacity to Attenuate Free Radicals, Protein Denaturation, and Cancer Proliferation.

Turmeric rhizomes (Curcuma longa) and black cumin seeds (Nigella sativa) are polyherbal ingredients used for the management of cancer and other chronic inflammatory diseases in Nigerian ethnomedicine. Previous studies have shown the antioxidant, anti-inflammatory, and anticancer activities of the individual plant extracts. However, the two spices have not been biologically potentiated in their combined form. Therefore, this study obtained essential oils (EOs) from the combined spices and evaluated their inhibitory effects on free radicals, protein denaturation, and cancer proliferation. The EOs were extracted by hydro-distillation (HD) and characterized by gas chromatography-mass spectrometry (GC-MS). In vitro antioxidant assessment was conducted based on DPPH, hydrogen peroxide (H2O2), nitric oxide (NO), and ferric ion (Fe3+) radical scavenging assays. The cytotoxicity of the oil against non-tumorigenic (HEK293) and cancerous (HepG2 and HeLa) cell lines was determined following the MTT cell viability assay. An in silico molecular docking analysis of the oil constituents was also performed. Six batches of EOs I-VI were afforded, comprising twenty-two major constituents, with aromatic Ar-turmerone being the most prominent compound. There was a marked improvement in the bioactivity of the oils upon repeated HD and as a combination. The batch VI oil exhibited the best activity, with a cytotoxicity (CC50) of 10.16 ± 1.69 µg/100 µL against the HepG2 cell line, which was comparable to 5-fluorouracil (standard, CC50 = 8.59 ± 1.33 µg/100 µL). In silico molecular docking suggested δ-curcumene, Ar-curcumene, Ar-turmerol, and Ar-turmerone among the promising compounds based on their high binding energy scores with NOX2, NF-κB, and mdm2 proteins. In conclusion, the oils from the turmeric-black cumin combined possess a considerable inhibition ability against free radicals, protein denaturation, and cancer proliferation. This study's findings further underscore the effectiveness of turmeric-black cumin as a polyherbal medicinal ingredient.

Investigation on Anti‐plasmodial Agents Against wild‐type PfDHFR Through In Silico Computational Tools

AbstractMalaria is the most severe and common parasitic infection, with P. falciparum responsible for the majority of cases and deaths each year. As anti‐malarial drug resistance continues to increase, novel compounds with anti‐ P. falciparum activity must be identified. In search of a new molecule to cure the resistant malarial parasite, a total of 1,70,269 ligands from the Asinex BioDesign library 2021.2 were virtually screened using AutoDock Vina against wild‐type P. falciparum dihydrofolate reductase‐thymidylate synthase (PfDHFR‐TS). The computational molecular modeling investigations indicated the discovery of seventeen new compounds (2‐18) with higher binding energy compared to the PfDHFR‐TS inhibitor, pyrimethamine (1). Furthermore, the study employing drug‐likeness criteria and their ADMET profile suggested that these hits were the most promising drug candidates due to higher absorption and druggability. Furthermore, GROMACS 2023.4 was used to perform the molecular dynamics simulations on the foremost compound (2) having sufficient stability, leading to a key step towards the search of novel PfDHFR‐TS inhibitors against malaria.

Performance evaluation of SILAR deposited Rb-Doped ZnO thin films for photodetector applications

ZnO-based photodetectors (PDs) compose a remarkable optoelectronic device field due to their high optical transmittance, electrical conductivity, wide band gap, and high binding energy. This study examined the visible light photodetector performance of the pristine and Rubidium (Rb)-doped ZnO thin films. The influence of Rb doping amount (2, 4, and 6 wt% in solution) on the electrical, optical, and structural properties of the ZnO-based thin films produced by the Successive Ion Layer Adsorption and Reaction (SILAR) technique was analyzed. Structural analyses showed that all peaks correspond to hexagonal wurtzite structure with no other peak from Rb-based phases, suggesting the high quality of the crystalline pristine and Rb-doped ZnO thin films. The morphology of the thin films shows homogenous layers formed of nanoparticles where particle size was first decreased and then increased with the increasing Rb doping according to Scanning Electron Microscope (SEM) morphology analysis. Besides that, Raman spectroscopy analyses indicate that the phonon lifetimes of the ZnO-based thin films slightly increased due to the improvement of the crystal quality with the increasing amount of Rb in the SILAR solution. Photosensor measurements of the nanostructured pristine and Rb-doped ZnO thin films were measured at different light power intensities under the visible light environment. Photosensor properties were examined depending on the doping amount and light power density. In light of the literature review, our study is the first to produce Rb-doped ZnO thin films via the SILAR method, which has a promising potential for photosensor applications.Graphical

Influence of Edges and Interlayer Electron-phonon Coupling in WS2/h-BN Heterostructure.

The semiconducting layered transition metal dichalcogenides (e.g., WS2) are excellent candidates for the realization of optoelectronic and nanophotonic applications on account of their band gap tunability, high binding energy and oscillator strength of the excitons, strong light-matter interaction, appreciable charge carrier mobility, and valleytronic properties. However, the photoluminescence (PL) emissions are reported to show a nonuniform spatial distribution, with the edges emitting features like defect-bound excitons and biexcitons at low temperatures in addition to the typical excitons and trions. The appearance of these additional PL features has been shown in the literature to have a strong dependence on the presence of S-vacancies and excess charge carriers. We demonstrate an enhancement of the defect-bound excitons and biexcitons by creating a heterostructure of WS2 with h-BN where the coupling between the charge carriers in WS2 with the polar phonons in h-BN governs the enhancement. Furthermore, we have performed a comprehensive resonant Raman study with varying polarization and magnetic field which not only confirms the presence of electron-phonon coupling in WS2/h-BN heterostructure, it further demonstrates a thermally induced differential resonance behavior with the excitonic level and the defect-induced midgap states (due to S-vacancies at the edge of WS2) exhibited by a dome-shaped behavior of the Raman intensities with temperature for the normal and defect-induced phonon modes. The defect-bound Raman modes exhibit maximum resonance at ∼240 K while normal Raman modes show at ∼280 K owing to a thermal variation of the electronic states.

In-silico screening of bioactive compounds of Moringa oleifera as potential inhibitors targeting HIF-1α/VEGF/GLUT-1 pathway against Breast Cancer.

Breast cancer is among the most heterogeneous and aggressive diseases and a foremost cause of death in women globally. Hypoxic activation of HIF-1α in breast cancers triggers the transcription of a battery of genes encoding proteins that facilitate tumor growth and metastasis and is correlated with a poor prognosis. Based on the reported cytotoxic and anti-cancer properties of Moringa oleifera (Mo), this study explores the inhibitory effect of bioactive compounds from M.oleifera and breast cancer target proteins HIF-1α, VEGF, and GLUT-1 in silico. The X-ray crystallographic structures of HIF-1α, VEGF, and GLUT1 were sourced from the Protein Data Bank(PDB) and docked with 70 3D PubChem structures of bioactive compounds of M.oleifera using AutoDock Vina, and binding modes were analyzed using Discovery Studio. Five compounds with the highest binding energies were selected and further drug-likeness, oral bioavailability, ADME, and toxicity profiles were analyzed using SwissADME, ADMETSaR, and ADMETlab 3.0 web server. Out of the screened 70 bioactive compounds, the top five compounds with the best binding energies were identified namely Apigenin, Ellagic Acid, Isorhamnetin, Luteolin, and Myricetin with each receptor. Molecular docking results indicated that the ligands interact strongly with the target HIF-1α, VEGF, and GLUT-1 receptors through hydrogen bonds and hydrophobic interactions. These compounds showed favorable drug-like and pharmacokinetic properties, possessed no substantial toxicity, and were fairly bioavailable. Results suggested that the compounds possess strong potential in developing putative lead compounds targeting HIF-1α that are safe natural plant-based drugs against breast cancer.

Stabilizing Zinc Anode through Ion Selection Sieving for Aqueous Zn-Ion Batteries.

Uncontrollable dendrite growth and corrosion induced by reactive water molecules and sulfate ions (SO42-) seriously hindered the practical application of aqueous zinc ion batteries (AZIBs). Here we construct artificial solid electrolyte interfaces (SEIs) realized by sodium and calcium bentonite with a layered structure anchored to anodes (NB@Zn and CB@Zn). This artificial SEI layer functioning as a protective coating to isolate activated water molecules, provides high-speed transport channels for Zn2+, and serves as an ionic sieve to repel negatively charged anions while attracting positively charged cations. The theoretical results show that the bentonite electrodes exhibit a higher binding energy for Zn2+. This demonstrates that the bentonite protective layer enhances the Zn-ion deposition kinetics. Consequently, the NB@Zn//MnO2 and CB@Zn//MnO2 full-battery capacities are 96.7 and 70.4 mAh g-1 at 2.0 A g-1 after 1000 cycles, respectively. This study aims to stabilize Zn anodes and improve the electrochemical performance of AZIBs by ion-selection sieving.

Revealing the key antioxidant compounds and potential action mechanisms of Chinese Cabernet Sauvignon red wines by integrating UHPLC-QTOF-MS-based untargeted metabolomics, network pharmacology and molecular docking approaches

In recent years, red wine drinking has become more popular in China owing to its antioxidant effects. However, the key antioxidant compounds and their action mechanisms of Chinese red wines are still unclear. Herein, the antioxidant activities and chemical compositions of 45 Chinese Cabernet Sauvignon red wine samples were determined using chemical antioxidant assays and an UHPLC-QTOF-MS-based untargeted metabolomics method. The key antioxidant compounds in red wines and potential action mechanisms were revealed by integrating network pharmacology and molecular docking approaches. Results showed that there are 8 key antioxidant compounds in the red wine samples. These compounds are involved in several metabolic pathways in the body, particularly PI3K/AKT. What's more, they bind to the core antioxidant targets through hydrogen bonding and hydrophobic interaction. Among them, myricetin, laricitrin, 2,3,8-tri-O-methylellagic acid and AKT1 have the highest binding energies. This study could provide the theoretical basis for further investigation of physiological activities and functions of Chinese red wines.

Ligand‐Pinning Induced Size Modulation of CsPbI3 Perovskite Quantum Dots for Red Light‐Emitting Diodes

AbstractPerovskite quantum dots (PQDs) show high potential for new‐generation light‐emitting diodes (LEDs) due to their outstanding optoelectronic properties. Even though the red PQD‐LEDs can be realized through mixing halide in the PQDs to tune their spectroscopies, the PQDs may suffer from phase separation under a high electric field, predominantly affecting LED applications. Herein, a ligand‐pinning‐assisted approach is reported to tune the spectroscopies of CsPbI3 PQDs, in which vinyl phosphonic acid (VPA) is applied as function ligands to regulate the nucleation and growth of PQDs during the synthesis. Systematically experimental studies and theoretical calculations are conducted to comprehensively understand the functions of the VPA ligands during the PQD synthesis, which reveals that the VPA ligands with high binding energy with Pb2+ cations could firmly anchor on the surface matrix of PQDs without desorption, regulating the growth of PQDs and thus resulting in tunable spectroscopies being realized. Meanwhile, VPA could also renovate the defective surface matrix of PQDs, substantially diminishing trap‐induced nonradiative recombination. Consequently, red PQD‐LEDs deliver a high external quantum efficiency of 22.83%, which is significantly improved compared with the control devices. This work provides a new avenue to tune the spectroscopies of PQDs toward high‐performing LEDs.

Organic-Inorganic Rubrene/WS2 Heterostructure for Broadband Detection and Polarization Imaging.

Organic single crystals exhibit improved carrier mobility, longer exciton diffusion length, anisotropic charge transport, and unique linear dichroism, while its high exciton binding energy seriously limits the free-carrier generation and photoelectric conversion efficiency. Layered van der Waals heterostructures, which integrate organic crystals with high mobility two-dimensional (2D) inorganic semiconductors, are promising for promoting exciton dissociation and boosting sensitivity by utilizing the interfacial potential and photogating effect. In this work, organic single-crystal rubrene is integrated with a few-layer WS2 to design the high-performance photodetector. The device exhibits an excellent responsivity of 1000 A W-1, and a fast speed of 180 μs, which is far superior to the individual WS2 device. Equally importantly, this device provides excellent polarization detection performance by virtue of the anisotropic properties of rubrene, and the dichroic ratios are 1.56, 1.5, and 1.7 for 375, 405, and 658 nm irradiation, respectively. Finally, several high-resolution single-pixel broadband polarization imaging was demonstrated. Our work shows that organic-inorganic heterostructure is an essential candidate for improving optoelectronics performance and has potential for polarization imaging.

Quantized Microcavity Polariton Lasing Based on InGaN Localized Excitons.

Exciton-polaritons, which are bosonic quasiparticles with an extremely low mass, play a key role in understanding macroscopic quantum effects related to Bose-Einstein condensation (BEC) in solid-state systems. The study of trapped polaritons in a potential well provides an ideal platform for manipulating polariton condensates, enabling polariton lasing with specific formation in k-space. Here, we realize quantized microcavity polariton lasing in simple harmonic oscillator (SHO) states based on spatial localized excitons in InGaN/GaN quantum wells (QWs). Benefiting from the high exciton binding energy (90 meV) and large oscillator strength of the localized exciton, room-temperature (RT) polaritons with large Rabi splitting (61 meV) are obtained in a strongly coupled microcavity. The manipulation of polariton condensates is performed through a parabolic potential well created by optical pump control. Under the confinement situation, trapped polaritons are controlled to be distributed in the selected quantized energy sublevels of the SHO state. The maximum energy spacing of 11.3 meV is observed in the SHO sublevels, indicating the robust polariton trapping of the parabolic potential well. Coherent quantized polariton lasing is achieved in the ground state of the SHO state and the coherence property of the lasing is analyzed through the measurements of spatial interference patterns and g(2)(τ). Our results offer a feasible route to explore the manipulation of macroscopic quantum coherent states and to fabricate novel polariton devices towards room-temperature operations.

Synthesis and study of the impact of calcination duration on the properties of Al4(ZnO)96 nanoparticles

Aluminium doped zinc oxide (Al4(ZnO)96) nanoparticles were synthesized using new sogel method at 40 °C, with zinc acetate dihydrate (Zn(CH3COO)2·2 H2O) and aluminium nitrate nonahydrate (Al(NO3)3·9 H2O) as precursors. The samples underwent analysis using various structural and optical techniques to investigate the effect of calcination duration on the properties. Prolonged calcination durations led to a significant reduction of oxygen at the grain boundaries, influencing particle size and crystallization. According to TEM-histogram analysis, the most probable size for 28.5 % of nanoparticles fell within the range of 15–20 nm, which aligns closely with the estimated particle size determined by XRD analysis. The material displayed a significant direct bandgap of approximately 3.283 eV, which increased with the duration of calcination. The band gap was affected by changes in phase, strain, and particle size, attributed to the presence of defect states and a substantial concentration of localized states. Additionally, the material exhibited excellent chemical stability and a significantly high binding energy. Moreover, the optical bandgap widened as the width of the Urbach tails in the localized states decreased with an increase in the duration of calcination.