Shubha Dubey, Vipin Kumar, Kumud Dubey, Kuldeep Singh, Marcus Einert, Dipti Gawande, R. K. Sharma, Gitanjali Pagare and N. K. Gaur
{"title":"Experimental and DFT analysis of antisite disorder and Griffiths phase in Dy2CoMnO6: structural, electronic, and magnetic insights†","authors":"Shubha Dubey, Vipin Kumar, Kumud Dubey, Kuldeep Singh, Marcus Einert, Dipti Gawande, R. K. Sharma, Gitanjali Pagare and N. K. Gaur","doi":"10.1039/D5TC00299K","DOIUrl":"https://doi.org/10.1039/D5TC00299K","url":null,"abstract":"<p >The intricate interaction of emergent degrees of freedom, ground state degeneracy, and competing magnetic interactions in oxide-based double perovskite frustrated magnets can give rise to exotic excitations and correlated quantum phenomena with promising technological applications. This study investigates the structural, magnetic, and electronic properties of Dy<small><sub>2</sub></small>CoMnO<small><sub>6</sub></small> synthesized <em>via</em> solid-state reaction. Rietveld refinement of XRD data confirms a monoclinic <em>P</em>2<small><sub>1</sub></small>/<em>n</em> structure, with Raman spectra revealing BO<small><sub>6</sub></small> polyhedral dynamics. XPS analysis indicates mixed valence states of Co and Mn. Magnetic measurements show ferromagnetic ordering below <em>T</em><small><sub>c</sub></small> = 87 K due to Co<small><sup>2+</sup></small>–Mn<small><sup>4+</sup></small> superexchange, along with a Griffiths phase above <em>T</em><small><sub>c</sub></small> (<em>T</em><small><sub>G</sub></small> = 91 K) and canted antiferromagnetic correlations at low temperature. A coercivity of 6.8 kOe at 10 K further supports FM behavior. Density functional theory (DFT) calculations validate the stability of Dy<small><sub>2</sub></small>CoMnO<small><sub>6</sub></small> in the ferromagnetic phase, showing that the ferromagnetic state is energetically more favorable than the antiferromagnetic state. The direct band gap of Dy<small><sub>2</sub></small>CoMnO<small><sub>6</sub></small> was found to be approximately 1.47 eV, while the indirect band gap was around 1.04 eV. Electronic band structure and density of states calculations predict band gaps of 1.60 eV and 3.20 eV for the minority and majority spin orientations, respectively, confirming the semiconductor nature of Dy<small><sub>2</sub></small>CoMnO<small><sub>6</sub></small>. These calculated values closely match the experimentally observed band gap.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 20","pages":" 10282-10301"},"PeriodicalIF":5.7,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Connor J. Dolan, Emma R. Yakel, Shiwei Liu, Ross A. Kerner, Jack R. Palmer, Kelly X. Vences, Hendrik M. Vossler, Clark Han, Sean P. Dunfield and David P. Fenning
{"title":"Single crystal purification reduces trace impurities in halide perovskite precursors, alters perovskite thin film performance, and improves phase stability†","authors":"Connor J. Dolan, Emma R. Yakel, Shiwei Liu, Ross A. Kerner, Jack R. Palmer, Kelly X. Vences, Hendrik M. Vossler, Clark Han, Sean P. Dunfield and David P. Fenning","doi":"10.1039/D4TC04654D","DOIUrl":"https://doi.org/10.1039/D4TC04654D","url":null,"abstract":"<p >Impurities present in commercially available halide perovskite precursors are known to affect photovoltaic performance. Here, we employ bulk single crystal growth of FAPbI<small><sub>3</sub></small> using solvent orthogonality induced crystallization (SONIC) to remove a broad set of extrinsic impurities from commercially available halide perovskite precursors, as verified by detailed chemical analysis. Following SONIC purification, FAPbI<small><sub>3</sub></small> films made from PbI<small><sub>2</sub></small> of originally low purity (99%) and high purity (99.99%) show improved phase purity and stability under light and heat relative to films made from raw precursors or precursors purified <em>via</em> retrograde powder crystallization (RPC) in 2-methoxyethanol, a method commonly utilized in recent reports of the highest-efficiency perovskite solar cells. Single-crystal purification of precursors improves film stability under operational stressors, and the large enhancements in material purity provide a cleaner slate for improved isolation of compositional and additive effects on perovskite phase stability.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 19","pages":" 9584-9592"},"PeriodicalIF":5.7,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mahima Rabari, Vasundhara Hegde, Gurumurthy Hegde and A. K. Prajapati
{"title":"Systematic investigation on unsymmetrical mesogenic cyanobiphenyl dimers towards optical storage devices: synthesis, mesomorphic, photo switching and DFT studies†","authors":"Mahima Rabari, Vasundhara Hegde, Gurumurthy Hegde and A. K. Prajapati","doi":"10.1039/D5TC00421G","DOIUrl":"https://doi.org/10.1039/D5TC00421G","url":null,"abstract":"<p >This research presents the synthesis and analysis of a novel series of mesogenic dimers comprising cyanobiphenyl and azonaphthyl units. Structural validation was performed using FT-IR, <small><sup>1</sup></small>H-NMR, <small><sup>13</sup></small>C-NMR, elemental analysis, mass spectrometry, <em>etc.</em> The dimers’ thermotropic behaviours were studied through POM and DSC, revealing enantiotropic nematic phases in all cases, with some also showing monotropic smectic C phases. The study explores the relationship between the chemical structure of the dimers and the length of the flexible spacer, the odd–even effect, and their phase transition temperatures. Longer chains tended to form smectic phases, while shorter chains primarily exhibited nematic phases. Computational analysis using B3LYP/6-31g(d,p) and evaluations of electrostatic potential (ESP) and optical properties provided further insight into the electronic structures. Photoisomerization studies demonstrated consistent photochromic responses, with all dimers showing high conversion efficiency (88–95%) under UV light along with similar back relaxation times (∼10–12 hours). Optical storage devices prepared by these materials showed excellent contrast between dark and bright states elucidating the importance of such materials for the future.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 21","pages":" 10700-10713"},"PeriodicalIF":5.7,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/tc/d5tc00421g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144171111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Theoretical design and validation of [1,2,4]triazolo[1,5-a]pyridine-based TADF emitters through donor and linkage variations†","authors":"Chetan Saini and K. R. Justin Thomas","doi":"10.1039/D5TC00602C","DOIUrl":"https://doi.org/10.1039/D5TC00602C","url":null,"abstract":"<p >Achieving an optimal balance between donor and acceptor strength, coupled with strategic variations in molecular linkage, is pivotal for designing efficient thermally activated delayed fluorescence (TADF) materials. In this study, we incorporate the electron-accepting [1,2,4]triazolo[1,5-<em>a</em>]pyridine (TP) unit to explore high-performance TADF emitters. Through a systematic investigation, we elucidate the relationship between molecular structure and photophysical properties by modulating donor strength and the linkage between donor and acceptor units <em>via</em> a phenyl spacer. Eighteen molecules featuring diverse donor substituents (<strong>Cz</strong>, <strong>DPA</strong>, <strong>DMAc</strong>, <strong>PTZ</strong>, <strong>PXZ</strong>, and <strong>NPP</strong>) and linkage configurations (<em>ortho</em>-, <em>meta</em>-, <em>para</em>-) were designed, and their photophysical properties were thoroughly analysed using density functional theory (DFT) and time-dependent DFT (TD-DFT) methods. Key parameters such as the singlet–triplet energy gap (Δ<em>E</em><small><sub>ST</sub></small>), spin–orbit coupling (SOC), charge transfer (CT) indices, root-mean-square deviation (RMSD), reorganization energies, and excited-state rate constants were evaluated to characterize their emission properties. Our results reveal that molecules with weak donors exhibit large Δ<em>E</em><small><sub>ST</sub></small> values due to significant overlap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). In contrast, molecules with moderate to strong donors demonstrate smaller Δ<em>E</em><small><sub>ST</sub></small> values, attributed to enhanced HOMO–LUMO separation and improved CT character. Notably, molecules with <em>meta</em>-linkages and moderate to strong donor groups exhibit Δ<em>E</em><small><sub>ST</sub></small> values below 0.1 eV, moderate SOC, and higher rates of intersystem crossing (<em>k</em><small><sub>ISC</sub></small>), reverse intersystem crossing (<em>k</em><small><sub>rISC</sub></small>), and radiative decay (<em>k</em><small><sub>r</sub></small>), making them ideal candidates for TADF emission. This study provides a comprehensive framework for the rational design of highly efficient TP-based TADF materials for OLED applications and serves as a valuable guide for experimentalists in developing next-generation TADF emitters.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 19","pages":" 9611-9624"},"PeriodicalIF":5.7,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sanu Bifal Maji, Alexander Vanetsev, Vitali Nagirnyi, Kirill Chernenko, Eduard Feldbach, Jekaterina Kozlova, Hugo Mändar, Ivo Romet, Mihkel Rähn and Marco Kirm
{"title":"Impact of crystallinity and local disorder on the luminescence properties of solvothermally synthesized LuPO4:Pr3+ nanocrystals†","authors":"Sanu Bifal Maji, Alexander Vanetsev, Vitali Nagirnyi, Kirill Chernenko, Eduard Feldbach, Jekaterina Kozlova, Hugo Mändar, Ivo Romet, Mihkel Rähn and Marco Kirm","doi":"10.1039/D5TC00391A","DOIUrl":"https://doi.org/10.1039/D5TC00391A","url":null,"abstract":"<p >In this study, we present the solvothermal synthesis of LuPO<small><sub>4</sub></small>:Pr<small><sup>3+</sup></small> (1%) nanocrystals in a dimethyl sulfoxide–water solvent system. The as-prepared nanocrystals exhibit a relatively high degree of crystallinity, along with significant short-range disorder, particularly in the anionic sublattice, as revealed by XRD and Raman spectroscopy data. Low temperature luminescence spectroscopy under VUV excitation showed that this disorder hinders the energy transfer from the host lattice to the Pr<small><sup>3+</sup></small> ions, resulting in the absence of the 4f<small><sup>1</sup></small>5d<small><sup>1</sup></small>→4f<small><sup>2</sup></small> emission under high energy excitation. Thermal annealing of as-prepared nanocrystals significantly reduces the degree of local disorders enhancing UV-C luminescence in the 4.4–5.5 eV range by improving energy transfer processes from the LuPO<small><sub>4</sub></small> host to Pr<small><sup>3+</sup></small> ions. Time-integrated luminescence spectra reveal up to a five-fold increase in UV-C emission intensity after annealing. UV-C emissions due to Pr<small><sup>3+</sup></small> ions in LuPO<small><sub>4</sub></small> are efficiently excited in the deep intrinsic absorption region at 45 eV, which simulates the energy conversion process for radiotherapy applications. Time-resolved studies identify two types of Pr<small><sup>3+</sup></small> ions. One group consists of strongly perturbed ions near the nanoparticle surface, influenced by structural imperfections, while the other includes weakly perturbed ions located in the bulk. These results highlight the critical role of local structural imperfections almost undetectable by XRD in energy transfer processes involving the host lattice.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 20","pages":" 10139-10151"},"PeriodicalIF":5.7,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/tc/d5tc00391a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sadaf Samiei, Gholamreza Nabiyouni, Ehsan Soheyli and Jean-Michel Nunzi
{"title":"ZnF2 modulation of a CsPbBr3@glass composite: a heat treatment-free approach to reach stable and bright green emission for backlight display devices","authors":"Sadaf Samiei, Gholamreza Nabiyouni, Ehsan Soheyli and Jean-Michel Nunzi","doi":"10.1039/D5TC00428D","DOIUrl":"https://doi.org/10.1039/D5TC00428D","url":null,"abstract":"<p >The unique combination of perovskite nanocrystals (PeNCs) and glass matrices offers a platform for the development of advanced optoelectronic materials with tailored luminescence characteristics, high quantum efficiency, and tunable emission wavelengths, along with exceptional stability against degradation. Herein, we successfully fabricated CsPbBr<small><sub>3</sub></small> perovskite@glass (PeG) composites with excellent stability and optical properties by optimizing the precipitation conditions of the PeNCs. It was found that the addition of ZnF<small><sub>2</sub></small> enhances the precipitation of PeNCs due to its etching effect while simultaneously reducing the activation energy for glass crystallization. This eliminated the need for the commonly used secondary heat-treatments during the glass fabrication process. The optimized composition exhibited bright green emission with a high photoluminescence quantum yield (PLQY) of 91%, narrow emission profiles of less than 30 nm, and average decay lifetimes of ∼11 ns. The strong protecting effect of the glass matrix on the luminescence characteristics of the PeNCs was also confirmed after one month of soaking in water. Furthermore, the ZnF<small><sub>2</sub></small>-doped PeG composites were dual-encapsulated <em>via</em> a polydimethylsiloxane (PDMS) polymer, and their potential ability in backlight displays was tested. The scalable, heat-treatment-free method, along with bright and durable emission, makes this novel composition ideal for practical applications like display pixels.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 20","pages":" 10378-10389"},"PeriodicalIF":5.7,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bhabana Priyadarshini Debata, Sabita Patel and Sivakumar Vaidyanathan
{"title":"Imidazo[1,5-a]pyridine–benzilimidazole conjugated (donor–π–acceptor) greenish-yellow fluorophores and their applications in white light-emitting diodes, acidochromism and anticounterfeiting†","authors":"Bhabana Priyadarshini Debata, Sabita Patel and Sivakumar Vaidyanathan","doi":"10.1039/D5TC01152C","DOIUrl":"https://doi.org/10.1039/D5TC01152C","url":null,"abstract":"<p >This work reports the design and synthesis of three D–π–A push–pull fluorophores (<strong>BPy-1</strong>, <strong>BPy-2</strong>, and <strong>BPy-FL</strong>) featuring flexible phenyl or rigid and sterically hindered diethylfluorene moieties. The role of spacer units in modulating their photophysical properties has been analyzed through DFT analysis and experimental findings. All the fluorophores are characterized by excellent intramolecular charge transfer (ICT) and positive solvatochromism with a large Stokes shift (∼7000 cm<small><sup>−1</sup></small>) due to the presence of the N1 functionalized benzilimidazole acceptor and the 1,3-diphenylimidazo[1,5-<em>a</em>]pyridine donor attached through a phenyl spacer in the case of <strong>BPy-1</strong> and <strong>BPy-2</strong> and a diethyl fluorene spacer in <strong>BPy-FL</strong>. <strong>BPy-1</strong> and <strong>BPy-2</strong> show strong greenish-yellow emission at around 520 nm in solution, solid, and thin-film matrices with a good quantum yield (∼70%). <strong>BPy-FL</strong> exhibits blue emission (<em>λ</em><small><sub>max</sub></small> = 458 nm) in THF solution and intense greenish-yellow emission (<em>λ</em><small><sub>max</sub></small> = 510 nm) in the solid state with an absolute quantum yield of 93%. The fluorophore <strong>BPy-FL</strong> shows aggregation-induced emission (AIE) and hybridized local charge transfer (HLCT) characteristics. The DFT analysis depicts the energy matching of high-lying triplet states (T<small><sub>4</sub></small>–T<small><sub>5</sub></small>) with the first excited singlet state, which is beneficial for hot exciton harvesting. Due to their strong greenish-yellow emissions in the solid state, these fluorophores are employed as organic downconverter materials in hybrid white light-emitting diodes (LEDs). Among the fabricated white LEDs, the LED consisting of <strong>BPy-FL</strong> demonstrated excellent luminous efficiency with a high color rendering index (CRI) of ∼90% and CIE coordinates (0.37,0.32) almost identical to the NTSC standard. Due to the bipolar nature of the imidazole ring, all these fluorophores display remarkable on–off–on fluorescence behavior in response to alternate addition of acid and base in solution as well as in a thin film state. These fluorophores are, therefore, successfully utilized as fluorescent pH sensors to detect volatile organic compounds with high acidity (an orange emissive state at pH < 4 and a greenish-yellow emissive state at pH > 4). The sensing mechanism has been studied through <small><sup>1</sup></small>H-NMR and DFT analyses. The potential of these fluorophores in anticounterfeiting applications has been studied, and due to intense emission in the solid state of <strong>BPy-FL</strong>, its application in latent fingerprint (LFP) detection has also been explored.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 20","pages":" 10413-10433"},"PeriodicalIF":5.7,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/tc/d5tc01152c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Exploration of rational donor–acceptor adjustment strategies to achieve ACQ to AIE transformation and their potential applications as multi-functional AIEgens†","authors":"Weiwei Zhang, Yongbo Wei, Fen Lin, Yinyin Yao, Xia Wang, Yongxiao Sun, Jingming Zhou, Tong Wu, Nannan Chen, Yusheng Lu, Xiaoping Wu and Lijun Xie","doi":"10.1039/D5TC00238A","DOIUrl":"https://doi.org/10.1039/D5TC00238A","url":null,"abstract":"<p >In this work, a new series of rofecoxib analogues were designed and synthesized by employing the migration of the donor (D) group and donor (D)–acceptor (A) switching principle to achieve ACQ–AIE conversion. Among them, when the D unit dimethylamino was anchored on the <em>para</em>-position of the benzene ring D, the corresponding compound <strong>L1</strong>, namely (<em>Z</em>)-5-(4-(dimethylamino)benzylidene)-4-(4-(methylsulfonyl)phenyl)-3-phenylfuran-2(5<em>H</em>)-one, was obtained exhibiting obvious aggregation-caused quenching (ACQ) behavior. Subsequently, after migrating the D group from ring D to ring B, the resulting <strong>L2</strong> exhibits an aggregation-induced emission (AIE) effect. Meanwhile, by switching the position of the D and A units based on the structure of <strong>L1</strong>, the corresponding compound <strong>L3</strong> also shows AIE behavior. These results demonstrate that migrating the position of the donor group and switching the positions of the donor and acceptor have significant effects on the fluorescent properties of the compounds. Moreover, single crystal X-ray analysis of <strong>L2</strong> and <strong>L3</strong> revealed that the stronger molecular C–H⋯π interactions contribute to greater structural rigidification, which in turn enhances their bright emission in the solid state. In addition, <strong>L2</strong> and <strong>L3</strong> exhibited solvatochromic, acidichromic, and trace water properties with reversible multi-stimulus behaviors. More importantly, <strong>L2</strong> and <strong>L3</strong> demonstrated highly specific fluorescent imaging ability (<em>R</em><strong><small><sub>L2</sub></small></strong> = 0.97, <em>R</em><strong><small><sub>L3</sub></small></strong> = 0.98) toward lipid droplets in living MCF-7 cells, with low cytotoxicity. In summary, the creative design concepts of adjusting the position of D and switching the positions of D and A units, as well as the ACQ to AIE conversion provide alternative ways for developing new multifunctional AIEgens, <strong>L2</strong> and <strong>L3</strong>.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 19","pages":" 9502-9512"},"PeriodicalIF":5.7,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Rapid and efficient microwave-assisted synthesis of Mn-doped cesium bromide to phase engineered cesium manganese bromide nanocrystals with color-tunable RGB emission†","authors":"Pragati Sahu and Shatabdi Porel Mukherjee","doi":"10.1039/D5TC00215J","DOIUrl":"https://doi.org/10.1039/D5TC00215J","url":null,"abstract":"<p >Lead-free perovskite nanocrystals (NCs) have attracted considerable attention due to their excellent optoelectronic properties. However, they generally exhibit broadband emission with poor color purity. Similarly, obtaining tunable red/green/blue (RGB) emissions from lead-free perovskite NCs is highly desirable for several display applications. However, directly synthesizing lead-free perovskite NCs with tunable RGB emission and high color purity remains challenging. Herein, we have developed a simple and rapid microwave-assisted (MW-AT) synthesis strategy for synthesizing Mn-doped CsBr [Mn<small><sup>2+</sup></small>:CsBr] to phase engineering of non-toxic and stable all-inorganic cesium manganese bromide perovskite NCs in a nonpolar solvent with tunable blue-green-red emission color with high color purity. The phase transition was triggered by changing the MnBr<small><sub>2</sub></small> concentration during the microwave synthesis: from Mn<small><sup>2+</sup></small>:CsBr (blue emission) to zero dimensional (0D) Cs<small><sub>3</sub></small>MnBr<small><sub>5</sub></small> NCs (green emission) to one dimensional (1D) CsMnBr<small><sub>3</sub></small> NCs (red emission). In addition, in a controlled moisture environment, both the 0D Cs<small><sub>3</sub></small>MnBr<small><sub>5</sub></small> and 1D CsMnBr<small><sub>3</sub></small> NCs were transformed into 0D Cs<small><sub>2</sub></small>MnBr<small><sub>4</sub></small>·2H<small><sub>2</sub></small>O NCs (blue emission), which could be inversely transformed back to their respective original phase <em>via</em> thermal annealing. Thus, our work highlights for the first time a rapid and efficient MW-AT synthesis strategy to obtain phase-pure tunable optical properties with high color purity from Mn-doped CsBr to cesium manganese bromide perovskite NCs <em>via</em> phase engineering, which can be further utilized in designing anti-counterfeiting and encryption materials for coding with high security and information concealment. Our work also provides a new avenue for exploring efficient MW-AT synthesis of other earth-abundant eco-friendly highly luminescent Pb-free perovskite NCs for future endeavors.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 19","pages":" 9465-9473"},"PeriodicalIF":5.7,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yiying Chen, Junlei Qi, Bin Wei, Ce-Wen Nan and YuanHua-Lin
{"title":"Strong polarization in paraelectric tungsten–bronze systems via bond engineering†","authors":"Yiying Chen, Junlei Qi, Bin Wei, Ce-Wen Nan and YuanHua-Lin","doi":"10.1039/D5TC00266D","DOIUrl":"https://doi.org/10.1039/D5TC00266D","url":null,"abstract":"<p >High-performance dielectrics with high permittivity (<em>κ</em>) as well as low loss (tan <em>δ</em>) are a fundamental requirement as crucial components for the miniaturization of electrical and electronics systems. Recently, tungsten–bronze paraelectrics have shown great promise as dielectrics with relatively high permittivity and low loss. We demonstrate substantial enhancements in permittivity for paraelectric ceramics through a bonding tailoring strategy by introducing Bi ions into the Ba<small><sub>4</sub></small>Nd<small><sub>28/3</sub></small>Ti<small><sub>18</sub></small>O<small><sub>54</sub></small> tungsten bronze structure. The introduction of heavy Bi ions with 6s electrons into the lattice expands it, breaks the symmetry, and tilts the M–O octahedron, resulting in <em>κ</em> being enhanced by more than two times, while the tan <em>δ</em> remains low. As a result, the Ba<small><sub>4</sub></small>(Bi<small><sub>0.5</sub></small>Nd<small><sub>0.5</sub></small>)<small><sub>28/3</sub></small>Ti<small><sub>18</sub></small>O<small><sub>54</sub></small> exhibits a high <em>κ</em> ∼200 with low tan <em>δ</em> ∼0.0004. This bonding strategy is expected to be generally applicable to tailoring dielectric and other related functionalities.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 18","pages":" 9358-9364"},"PeriodicalIF":5.7,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}