Journal of Materials Chemistry C最新文献

{"title":"Selective gas phase pulsed etching of oxides with NbCl5","authors":"Juha Ojala, Marko Vehkamäki, Mykhailo Chundak, Anton Vihervaara, Kenichiro Mizohata and Mikko Ritala","doi":"10.1039/D4TC03488K","DOIUrl":"https://doi.org/10.1039/D4TC03488K","url":null,"abstract":"<p >Ta<small>₂</small>O<small>₅</small> films were etched with NbCl<small>₅</small> using a chemical vapor etching method known as gas-phase pulsed etching (GPPE) where the etchant is delivered in short pulses with inert gas purging in between the pulses. Arrhenius type dependence of etch per cycle (EPC) on temperature was found at 275–375 °C and the activation energy of the etching reaction is estimated at 120 kJ mol<small>⁻¹</small>. Length of the etchant pulse had a linear effect on EPC and increasing the purge length also increased EPC. Roughnesses of the partially etched films increased from 0.2 to 1.4 nm, as measured by atomic force microscopy. No residual Nb or Cl was detected in the films by energy-dispersive X-ray spectroscopy, but a small amount of Cl residue was seen with <em>in vacuo</em> X-ray photoelectron spectroscopy. Etching of TiO<small>₂</small> and ZrO<small>₂</small> was also observed but HfO<small>₂</small> was not etched by NbCl<small>₅</small> at 300–400 °C. Selectivity with respect of SiO<small>₂</small>, Al<small>₂</small>O<small>₃</small>, and TiN was also proven at the same temperature range. EPC up to 2.8, 1.1, and 4.0 Å were observed for Ta<small>₂</small>O<small>₅</small>, ZrO<small>₂</small>, and TiO<small>₂</small>, respectively.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 5","pages":" 2347-2355"},"PeriodicalIF":5.7,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/tc/d4tc03488k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107648","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":"Application of downshifting and antireflection stacked layers synthesized using a wet chemistry method with broad UV excitation for silicon heterojunction solar cells†","authors":"Xiaowen Zhao, Chuangen Xu, Jindi Wei, Haobo Wang, RuiPeng Yang, Xiaoliang Wang and Xiaojun Ye","doi":"10.1039/D4TC02353F","DOIUrl":"https://doi.org/10.1039/D4TC02353F","url":null,"abstract":"<p >Silicon heterojunction (SHJ) solar cells have enormous application prospects due to their high efficiency and small carbon footprint. However, during long-term use, the i-a-Si passivation layer of heterojunction (SHJ) solar cells tends to be destroyed by ultraviolet radiation, causing performance degradation. To eliminate this impact, downshifting (DS) materials of YVO<small>₄</small>:Eu<small>³⁺</small>,Bi<small>³⁺</small> on the glass surface absorb ultraviolet light and convert it to wavelengths with a higher spectral response of SHJ solar cells. Furthermore, adding anti-reflection (AR) layers on the DS layer's surface will help maintain high transmittance and weather resistance. YVO<small>₄</small>:Eu<small>³⁺</small>,Bi<small>³⁺</small> is prepared by using a wet chemical method, with no need for additional manufacturing of phosphors. The DS layer achieves uniform luminescence and expands the excitation spectrum. The average transmittance of glass coated with downshifting and anti-reflection (DSAR) is 96.80%, higher than that of glass with AR only. After high temperature and high humidity tests, the average transmittance of DSAR glass and the short-circuit current density of the module decreased by 1.44% and 0.59 mA cm<small>⁻²</small>, much lower than that of AR coating (decreased) samples, which decreased by 2.53% and 1.43 mA cm<small>⁻²</small>. After the UV test, the luminous intensity of the DSAR layer is much higher than that of the DS layer. Therefore, the DSAR layer could offer an easy industrialization approach to improve the outdoor reliability of SHJ solar cells.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 5","pages":" 2356-2366"},"PeriodicalIF":5.7,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107649","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":"High quality white light emission from Sb3+, Tb3+ and Mn2+ co-doped Cs2NaScCl6 double perovskites†","authors":"Deyuan Yang, Ruirui Cui and Chaoyong Deng","doi":"10.1039/D4TC03589E","DOIUrl":"https://doi.org/10.1039/D4TC03589E","url":null,"abstract":"<p >Recently, the splendid strategy of co-doping ns<small>²</small> electron configuration ions with rare-earth ions in all-inorganic lead-free halide double perovskites has been proposed to overcome the weak absorption cross-section of the f–f transition of rare-earth ions and achieve efficient white emission. But few of them can really provide effective red emission in lead-free halide double perovskites, despite the wide variety of rare-earth ions, and lead-free halide double perovskites with co-doping rare-earth ions and doping ns<small>²</small> electron configuration ions usually exhibit an unsatisfactory color rendering index due to the narrow characteristic emission peaks of rare-earth ions. To address this issue, Mn<small>²⁺</small> ions with red wide peak emission were introduced into Cs<small>₂</small>NaScCl<small>₆</small> simultaneously with Tb<small>³⁺</small> ions and Sb<small>³⁺</small> ions in this work. The white light emission was observed in Cs<small>₂</small>NaScCl<small>₆</small>:0.01Sb<small>³⁺</small>,0.12Tb<small>³⁺</small>,0.07Mn<small>²⁺</small> under 336 nm excitation because the presence of energy transfer from Sb<small>³⁺</small> ions to Mn<small>²⁺</small> and Tb<small>³⁺</small> ions enhances fluorescence performances of Mn<small>²⁺</small> and Tb<small>²⁺</small>. The temperature-dependent spectrum of Cs<small>₂</small>NaScCl<small>₆</small>:0.01Sb<small>³⁺</small>,0.12Tb<small>³⁺</small>,0.07Mn<small>²⁺</small> shows that it exhibits a stable white emission in the temperature range of 298–398 K, and it's emission intensity at 398 K only decreases by less than 18% of the initial intensity (at 298 K). Excitingly, WLED devices with a quite high color rendering index of 93.6, which is one of the best in lead-free halide double perovskites, and nearly standard white light CIE coordinates of (0.3425, 0.3435), have been fabricated by using Cs<small>₂</small>NaScCl<small>₆</small>:0.01Sb<small>³⁺</small>,0.12Tb<small>³⁺</small>,0.07Mn<small>²⁺</small> and a 340 nm LED chip and can maintain a good white color stability at different working times and currents. These results indicate that Cs<small>₂</small>NaScCl<small>₆</small>:Sb<small>³⁺</small>,Tb<small>³⁺</small>,Mn<small>²⁺</small> is an outstanding candidate for WLED applications.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 5","pages":" 2247-2256"},"PeriodicalIF":5.7,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107442","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":"Synthesis by size focusing of lithium tantalate nanoparticles with a tunable second harmonic optical activity†","authors":"Rana Faryad Ali and Byron D. Gates","doi":"10.1039/D4TC03938F","DOIUrl":"https://doi.org/10.1039/D4TC03938F","url":null,"abstract":"<p >Nonlinear optics at the nanoscale has emerged as a sought-after platform for sensing and imaging applications. The development of these materials is having an impact on fields that include advanced information technology, signal processing circuits, and cryptography. Lithium tantalate (LiTaO<small>₃</small>) is an attractive nonlinear optical material due to its high optical damage threshold (<em>e.g.</em>, tolerance to &gt;500 MW cm<small>⁻²</small> from a nanosecond pulsed laser) and broad range of ultraviolet-visible (UV-vis) transparency (<em>i.e.</em>, 0.28–5.5 μm) relative to many other nonlinear optical materials (<em>e.g.</em>, niobates, titanates). Despite many synthetic reports on metal oxides, very little is known about the preparation of uniform, crystalline LiTaO<small>₃</small> nanoparticles (NPs) of a pure phase, as well as details on their mechanism of nucleation and growth. In this article, we introduce a solution-phase method for the preparation of LiTaO<small>₃</small> NPs with tunable dimensions. This solution-phase process results in the formation of crystalline, uniform NPs of LiTaO<small>₃</small> of a pure phase when carried out at 220 °C. This method can prepare crystalline LiTaO<small>₃</small> NPs without the need for further heat treatment or the use of an inert atmosphere. Results presented herein also provide insights into the growth mechanism of these NPs. The reaction included the processes of oriented attachment and Ostwald ripening. The results of our study also indicate that the growth of the LiTaO<small>₃</small> NPs was a result of a “size focusing” effect, which enables the ability to tune their diameters from 200 to 500 nm. The crystalline NPs were optically active towards second harmonic generation (SHG). These studies deepen our understanding of the methods by which NPs can be prepared from metal oxides. These studies specifically demonstrate the preparation of optically active LiTaO<small>₃</small> NPs of uniform and controllable dimensions that could be used in a broad range of fundamental studies and applications in nanophotonics.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 5","pages":" 2312-2321"},"PeriodicalIF":5.7,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107672","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":"A polyurea interface structure with dual dynamic bonds endowing composites with synchronous self-healing and thermal conductivity properties†","authors":"Shuang Geng, Bin Wu, Yan Wu, Ping Yu, Ru Xia and Jiasheng Qian","doi":"10.1039/D4TC04088K","DOIUrl":"https://doi.org/10.1039/D4TC04088K","url":null,"abstract":"<p >Polymer-based thermal management materials in electronic devices suffer from molecular structure damage under long-term mechanical injury and temperature difference changes, which degrades performance. However, the construction of composites with self-repairing and heat dissipation properties is still a challenge to be solved. Herein, a dual-functional polyurea (D-PUA)-based self-healing thermal conductive composite (IPDI@GO<small>_<em>x</em></small>/D-PUA) was prepared <em>via in situ</em> polymerization of isophorone diisocyanate modified GO (IPDI@GO), terephthalaldehyde, and polyetheramine. Based on the D-PUA chain established between graphene nanosheets, heat transmission at the inner interface of the composite was realized, and the self-healing performance was ensured <em>via</em> interchain hydrogen bonds and intrachain imine bonds. The in-plane thermal conductivity (<em>κ</em><small>_‖</small>) of up to 2.7 W m<small>⁻¹</small> K<small>⁻¹</small> and the tensile strength of 17.5 MPa of IPDI@GO<small>_12.5</small>/D-PUA illustrated its structural advantages. Significantly, <em>κ</em><small>_‖</small> and stress self-healing efficiency of the composite were more than 90% after undergoing three self-healing processes of scratching, cutting and fragment remodeling. The integration of graphene into a polymer matrix with dynamic bonds to form an integrated composite provides a new idea for constructing high-performance heat management materials with dual-effect coupling for self-healing and thermal conductivity.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 5","pages":" 2271-2278"},"PeriodicalIF":5.7,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107444","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":"Boosting room-temperature thermoelectricity in SrTiO3-based superlattices†","authors":"Yi Zhu, Wenzhao Wang, Bokai Liang, Wei Liu, Tao Zhou, Biwei Meng, Hao Liu, Wenping Gao, Yulong Yang, Chang Niu, Changlin Zheng, Zhenhua An, Shiwei Wu, Weitao Liu, Yuqiao Zhang, Chao Yuan, Yinyan Zhu, Lifeng Yin and Jian Shen","doi":"10.1039/D4TC04200J","DOIUrl":"https://doi.org/10.1039/D4TC04200J","url":null,"abstract":"<p >Despite the breakthrough of heavy-metal-based thermoelectric materials, achieving high performance for environmentally friendly oxide-based thermoelectric materials is still a big challenge. In this work, we introduced tensile strain into the [(SrTiO<small>₃</small>)<small>_<em>m</em></small>/(SrTi<small>_0.8</small>Nb<small>_0.2</small>O<small>₃</small>)<small>_<em>n</em></small>]<small>_<em>t</em></small> superlattices using DyScO<small>₃</small>(110) substrates for epitaxial growth. The tensile strain effectively increased the ferroelectric transition temperature (<em>T</em><small>_C</small>) of the SrTiO<small>₃</small> superlattices from 105 K to 250 K. The phonon scattering due to the ferroelectric domain wall and soft phonon mode cumulatively lowered the thermal conductivity, boosting the dimensionless figure of merit (<em>ZT</em>) to 1.2 and power factor (<em>PF</em>) to 10.5 mW m<small>⁻¹</small> K<small>⁻²</small> at 300 K. These results suggest that tuning epitaxial strain is highly effective in enhancing thermoelectricity when combined with phonon-glass electron-crystal strategy, paving a new route for designing high-performance oxide-based thermoelectric materials.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 5","pages":" 2279-2285"},"PeriodicalIF":5.7,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107445","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":"Design of a photocatalyst combining graphdiyne–Cu/NiCrO3 with Cu as an interfacial charge-transfer bridge and investigation of its photocatalytic hydrogen evolution performance†","authors":"Lu Ding and Zhiliang Jin","doi":"10.1039/D4TC03677H","DOIUrl":"https://doi.org/10.1039/D4TC03677H","url":null,"abstract":"<p >The photocatalysts are closely combined and interact with each other, providing significant advantages for long-term solar–fuel conversion and contributing to enhanced photocatalytic efficiency. In this work, a graphdiyne–Cu/NiCrO<small>₃</small> composite photocatalyst was synthesized for the first time for highly promoted photocatalytic hydrogen evolution driven by visible light. The suitable band structures of graphdiyne and NiCrO<small>₃</small> and the interaction between them greatly improved the separation efficiency of photogenerated carriers. When Cu was loaded onto graphdiyne, it acted as an effective solid electronic medium, significantly increasing the charge-transfer rate during photocatalysis. At the same time, the strong electrical conductivity of the metal copper was conducive to the conduction of electrons. Tightly bound graphdiyne–Cu/NiCrO<small>₃</small> improved charge-separation efficiency, and the hydrogen evolution rate reached 1480 μmol g<small>⁻¹</small> h<small>⁻¹</small>. The incorporation of graphdiyne–Cu into NiCrO<small>₃</small> could effectively isolate oxidation sites, thereby improving the carrier-separation rate and hydrogen-precipitation efficiency.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 5","pages":" 2257-2270"},"PeriodicalIF":5.7,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107443","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":"High emission quantum yields and color-tunable properties of Ln-chelates embedded in PMMA†","authors":"Aneta Lipa, Yen Hoang Pham, Albano N. Carneiro Neto, Viktor A. Trush, Huanrong Li, Oscar L. Malta, Volodymyr M. Amirkhanov and Paula Gawryszewska","doi":"10.1039/D4TC03939D","DOIUrl":"https://doi.org/10.1039/D4TC03939D","url":null,"abstract":"<p >This research presents a series of PMMA thin layers (labelled <strong>Ln_PMMA</strong>, where Ln = Eu<small>³⁺</small>, Tb<small>³⁺</small>, Sm<small>³⁺</small>, Dy<small>³⁺</small>) with high overall emission quantum yields of <em>Q</em><small>^L</small><small>_Eu</small> = 85%, <em>Q</em><small>^L</small><small>_Tb</small> = 66%, <em>Q</em><small>^L</small><small>_Sm</small> = 3%, and <em>Q</em><small>^L</small><small>_Dy</small> = 6% with introduced lanthanide (Ln<small>³⁺</small>) coordination compounds of the type [Na<small>₂</small>LnL<small>₄</small>(OTf)(DMF)] (where L = <em>N</em>-(diphenylphosphoryl)-pyrazine-2-carboxamide, OTf = [CF<small>₃</small>SO<small>₃</small>]<small>⁻</small>, DMF = <em>N</em>,<em>N</em>-dimethylformamide). This is the first analysis comparing the photophysical properties of coordination compounds encapsulated in PMMA with single crystals, which includes the influence of factors such as the inhomogeneity of the Ln<small>³⁺</small> coordination polyhedra and the refractive index. A model is proposed to estimate the change in <em>Q</em><small>^L</small><small>_Ln</small> when the Ln chelate is incorporated into a PMMA medium, and it satisfactorily reproduces the experimental data with a maximum absolute error of 3% for the case of Eu<small>³⁺</small> samples. At the same time, our work shows the influence of the PMMA matrix on the photophysical properties of Ln<small>³⁺</small> with large (Eu, Tb) and small energy gaps (Sm, Dy) between the emitting levels and adjacent levels with lower energy. <em>Q</em><small>^L</small><small>_Ln</small> for coordination compounds introduced into PMMA decreases relative to single crystals by about 10% for Eu<small>³⁺</small> and Tb<small>³⁺</small> as well as by about 70% for Sm<small>³⁺</small> and Dy<small>³⁺</small> for which emitting levels are quenched by the electron–phonon coupling presented by the vibrational modes of the PMMA matrix. <strong>Ln_PMMA</strong> thin layers containing a mixture of Eu<small>³⁺</small>, Tb<small>³⁺</small>, Sm<small>³⁺</small> and Dy<small>³⁺</small> coordination compounds are characterized by multicolor tunable emission.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 5","pages":" 2142-2153"},"PeriodicalIF":5.7,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107483","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":"A flexible piezoelectric sensor based on a piezoelectric composite film with high sensitivity and excellent thermal stability for multi-scenario applications†","authors":"Chungang Li, Changhong Yang, Yaoting Zhao, Gensheng Dong, Xiujuan Lin and Shifeng Huang","doi":"10.1039/D4TC03512G","DOIUrl":"https://doi.org/10.1039/D4TC03512G","url":null,"abstract":"<p >With the development of basic facilities around the world, irregular curved structures are continuously emerging, so it is of great significance to conduct flexible sensing studies on complex curved surfaces. However, the traditional piezoelectric ceramics are seriously restricted in their application to structures with curved surfaces due to their inherent stiffness, brittleness, and low Curie temperature. Herein, we report a flexible piezoelectric composite film based on BiScO<small>₃</small>–PbTiO<small>₃</small>–(Sr<small>_0.7</small>Bi<small>_0.2</small>)TiO<small>₃</small> (BS–PT–SBT) piezoelectric ceramic particles and a polyimide (PI) matrix. The as-fabricated film shows a large voltage output of ∼112 V, a maximum current output of ∼454 nA, a high sensitivity of 6.56 V N<small>⁻¹</small>, and good temperature stability at 30–210 °C. In practical applications, it can serve as a functional component in a strain sensor, ultrasonic sensor, and acoustic emission sensor. Of particular significance is that the devices can monitor the water flow change process in a circular pipe, act as a vehicle counter on a curved road, and also be applied to the health monitoring of curved concrete and pipeline structures under high-temperature environments. This work demonstrates that the BS–PT–SBT–PI composite film exhibits enormous potential for sensing applications in multiple scenarios.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 4","pages":" 2010-2021"},"PeriodicalIF":5.7,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107530","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":"Fluorescence modulation of pyridinium betaines: a mechanofluorochromic investigation†","authors":"Peter W. McDonald, Jingjing Xu, Dale R. Lonsdale, Isabelle Jones, Benjamin Poggi, Rosalind P. Cox, Stéphane Aloise, Andrew D. Scully, Clémence Allain, Laurence Bodelot, Stephen A. Moggach, Toby D. M. Bell, Rémi Métivier, Sebastian G. B. Furness, Lars Goerigk and Chris Ritchie","doi":"10.1039/D4TC04290E","DOIUrl":"https://doi.org/10.1039/D4TC04290E","url":null,"abstract":"<p >A reversible change in a material's fluorescence spectrum on the application of force is known as mechanofluorochromism (MFC) and is a well-established field of study. However, the mechanism(s) responsible for the chromism may be different for each new material and it is important to elucidate these for many reasons, including the rational design of new analogues with targeted properties. Herein, the photophysical properties and mechanistic understanding of two MFC pyridinium betaines are reported. The emission sensitivity is explained by the coexistence of crystalline and amorphous phases after the application of mechanical force, with increased conformational flexibility in the amorphous phase facilitating red-shifts in emission. This explanation is supported by evidence from a range of spectroscopic techniques, including electron diffraction (ED) and fluorescence lifetime imaging microscopy (FLIM) mapping, two techniques that have, to the best of our knowledge, not been applied in the field of MFC to mechanically ground particles. For one of the compounds, ED on ground microcrystallites shows unambiguously that the same crystalline phase is retained after grinding, along with an amorphous contribution, providing direct evidence for the crystalline-amorphous mechanism, and the presence of these two phases is further supported by FLIM mapping. We envision these techniques will be highly instructive for the analysis of similar materials.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 48","pages":" 19371-19385"},"PeriodicalIF":5.7,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810794","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}