ACS Applied Optical Materials最新文献

{"title":"Quantum Dot-Based Ratiometric Optical Nanosensor for Machine Learning-Assisted Visual and Spectral Speciation of Arsenite and Arsenate","authors":"Razieh Motamedi-Khozani,&nbsp;Samira Abbasi-Moayed,&nbsp;Mohammad Reza Hormozi-Nezhad","doi":"10.1021/acsaom.6c00252","DOIUrl":"https://doi.org/10.1021/acsaom.6c00252","url":null,"abstract":"<p>Arsenic contamination in drinking water remains a majorglobalpublic health concern. Because arsenic toxicity depends strongly onits chemical form, speciation analysis is essential for understandingits environmental behavior, toxicity, and bioavailability. Althoughlaboratory-based techniques provide accurate measurements, there isan increasing demand for portable and cost-effective platforms capableof on-site detection and discrimination of inorganic arsenic species.In this study, a ratiometric fluorescent platform was developed forthe spectral and visual speciation of arsenite (AsO₃^3–) and arsenate (AsO₄^3–). The sensing strategy relies on fluorescence quenching of a mixtureof green-emissive thioglycolic acid-capped CdTe quantum dots (GQDs)and red-emissive mercaptopropionic acid-capped CdTe quantum dots (RQDs)by glutathione (GSH). Upon exposure to AsO₃^3– or AsO₄^3–, fluorescence was restoredto different extents, generating distinct response patterns that enabledarsenic speciation within 25 min. Under optimized conditions, theproposed “on–off–on” nanosensor enableddetermination of AsO₃^3– and AsO₄^3– over concentration ranges of 0.70–50and 0.15–20.00 μmol L^–1, respectively,with detection limits of 0.21 μmol L^–1 forAsO₃^3– and 0.06 μmol L^–1 for AsO₄^3–. Linear discriminant analysis(LDA) was identified as the optimal machine-learning model, achievingclassification accuracies above 93.0%. Application to spiked groundwaterand wastewater samples yielded recoveries of 90.0–110.0%, RSDsof 0.3–8.9%, and a classification accuracy of 97.2%. RGB dataextracted from fluorescence color patterns using a smartphone-basedimaging cabinet were also successfully applied to arsenic discriminationand quantification. By integrating ratiometric fluorescence sensing,smartphone imaging, and machine-learning-assisted classification,the proposed platform provides a portable, cost-effective, and user-friendlystrategy for arsenic speciation with potential for environmental monitoringand point-of-use water quality assessment.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"4 8","pages":"2313–2325"},"PeriodicalIF":3.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148858987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zirconium-Assisted Cd-MOF Ionic Liquid Multiresponsive Nanocomposite for Sequential Fluorescent Sensing of H2S","authors":"Indu Sharma,&nbsp;Arunima Das,&nbsp;Jyoti Sharma,&nbsp;Subash Chandra Sahoo,&nbsp;Mohit Kumar,&nbsp;Arvind Kumar,&nbsp;Vinod Kumar,&nbsp;Ramesh Kataria","doi":"10.1021/acsaom.6c00348","DOIUrl":"https://doi.org/10.1021/acsaom.6c00348","url":null,"abstract":"<p>Theunique physicochemical properties of ionic liquids allow them to interactspecifically with the targeted analyte. When combined with the multifunctionalfeatures of MOFs, ionic liquids can enhance their efficacy for selectiveand precise detection. To our knowledge, sensors based on the integrationof MOFs with ionic liquids are largely unexplored. Additionally, thereexist numerous semiconductor-based sensors for H₂S, yetfluorescence-based sensing remains a potential sensing pursuit. Thepresent study introduces a sequential fluorescence nanosensor withaugmented performance for both zirconium ions Zr(IV) and H₂S developed from cadmium-based MOF (PUC-12) and ionic liquid trihexyl(tetradecyl)phosphoniumbromide (IL1). Comprehensive characterization utilizing PXRD, TGA,HR-TEM, TRFS, FE-SEM, FT-IR analysis, etc., revealed the robust structuraland functional attributes of PUC-12 and the nanocomposite (PIL-15).PIL-15 demonstrated remarkable selectivity and sensitivity (LOD =0.25 μM; <em>K</em>_sv value = 0.24 ×10⁶ M^–1) for Zr(IV) ion detection inaqueous samples. The synergistic interplay of Zr(IV) and PIL-15 facilitatedan innovative fluorescence-based turn “off–on–off”nanosensor for H₂S (LOD = 1.7 μM; <em>K</em>_sv = 0.32 × 10⁷ M^–1),distinguishing itself from conventional semiconductor-based sensors.Mechanistic insights into the sensing processes were meticulouslyinvestigated using BET surface area analysis, XPS, and zeta potentialanalysis, providing a comprehensive understanding of the possibleinteractions. The nanosensor with a size of 33.14 nm demonstratedefficient stability (depicted by ICP-MS analysis) and sensing activitiesnot only in aqueous media but also in H₂S-responsive detectionin a biological environment as well. The results were validated usingRAW 264.7, an immortalized mouse macrophage cell line, achieving adetection limit (LOD) of 5.45 μM. A filter paper-based testwas further performed, confirming the reliability and portabilityof the sensing platform. The functioning of the proposed sensor isillustrated through an IMPLICATION logic gate system. Additionally,the sensor exhibited potential for real-world applications by successfullydetecting H₂S in wine samples, emphasizing its versatilityand practicality.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"4 8","pages":"2454–2470"},"PeriodicalIF":3.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148859071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Narrowband Far-Red Emitting Sr2ZnAl22O36:Mn4+ Spinel Phosphor for Integrated Horticultural LED, Optical Thermometry, and Forensic Fingerprint Imaging","authors":"Jatin Dhanuka,&nbsp;Monalisha Behera,&nbsp;Sudipta Som,&nbsp;Divya Janardhana,&nbsp;Shivaramu Nagarasanakote Jayaramu,&nbsp;Somrita Dutta,&nbsp;Parijat Pallab Jana,&nbsp;Hendrik C. Swart,&nbsp;Subrata Das","doi":"10.1021/acsaom.6c00313","DOIUrl":"https://doi.org/10.1021/acsaom.6c00313","url":null,"abstract":"<p>A fundamental trade-off between photophysical performanceand hoststability continues to constrain practical deployment of Mn⁴⁺-doped phosphors, even as their narrow-band far-red emission (650–730nm) attracts growing interest across lighting, sensing, and securityapplications. Fluoride hosts such as K₂SiF₆:Mn⁴⁺ achieve IQE &gt; 90%, yet moisture-induced hydrolytic degradationremains a critical reliability barrier. Oxide alternatives, thoughthermally stable, are encumbered by broad spectral output (fwhm &gt;50 nm), incomplete octahedral site occupancy, accelerated nonradiativedecay, and suppressed IQE below 50%. Moreover, phosphors simultaneouslysatisfying thermometric relative sensitivity (<em>S</em>_r) &gt; 0.3% K^–1 and Michelson contrast &gt;0.8in latent fingerprint (LFP) detection have not been demonstrated withina single composition. To address these issues, Mn⁴⁺-activatedSr₂ZnAl₂₂O₃₆ (SZAO:Mn⁴⁺) was synthesized via controlled solid-state calcination (1400 °C,6 h), yielding phase-pure material (&gt;99%) with Mn⁴⁺ preferentiallysubstituting distorted AlO₆ octahedral sites. UV-blue excitationproduces narrow-band far-red emission at 657 nm (IQE ∼ 63%),attributed to spin-forbidden ²E_g → ⁴A_2g transitions. Spectral congruence with phytochromeP_r and P_fr absorption supports application inphosphor-converted LEDs for controlled environment crop production.Thermally resolved photoluminescence measurements yield a quenchingactivation energy (<em>E</em>_a) of 0.61 eV, andthermoluminescence glow-curve deconvolution confirms multiple discretetrap-state populations modulating carrier recombination kinetics.Fluorescence intensity ratio analysis affords noncontact optical thermometryat <em>S</em>_r of 0.50% K^–1.Under UV excitation, SZAO:Mn⁴⁺ resolves level 3 ridge minutiaeacross chemically and texturally diverse substrates (Michelson contrast= 0.92), demonstrating forensic-grade LFP discrimination. Taken together,these findings position SZAO:Mn⁴⁺ as a structurally robust,host-versatile platform integrating far-red phosphor conversion, luminescencethermometry, and LFP detection.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"4 8","pages":"2368–2382"},"PeriodicalIF":3.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148858996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polarization-Encoded Breath Biomarker Fingerprinting via the Dielectric Anisotropy of BeS Thin Films","authors":"Sudipta Saha,&nbsp;Shoumik Debnath,&nbsp;Md. Kawsar Alam","doi":"10.1021/acsaom.6c00317","DOIUrl":"https://doi.org/10.1021/acsaom.6c00317","url":null,"abstract":"<p>Berylliumsulfide (BeS) is a wide-bandgap II–VIchalcogenidewhose permittivity tensor responds anisotropically to molecular adsorption,with the in-plane component <em>ε</em>_<em>yy</em> and the out-of-plane component <em>ε</em>_<em>zz</em> perturbed by different amounts dependingon the adsorbed species. We model a silicon microring resonator conformallycoated with a 10 nm BeS film and show computationally that this anisotropyis sufficient to distinguish five exhaled-breath volatile organiccompounds (acetone, isoprene, 4-hydroxyhexenal, 2-propenal, and benzene)from a single unfunctionalized resonator. Density functional theorycalculations of the BeS dielectric tensor under each adsorbate providethe optical properties of the material. Three-dimensional finite-differencetime-domain simulations of the coated ring show that the transverse-electric(TE) mode couples to <em>ε</em>_<em>yy</em> and the transverse-magnetic (TM) mode couples to <em>ε</em>_<em>zz</em>, producing two independent resonanceobservables per simulation. The TE shift is the same for all fiveanalytes at 0.263 nm and acts as a concentration reference; the TMshift ranges from 0.200 to 0.426 nm and is analyte specific. Benzeneis further separated by a sign inversion in TM transmission amplitudethat none of the other gases reproduce. TE sensitivities reach 5.1nm/RIU. TM sensitivities reach 6.5 nm/RIU. Figures of merit reach14.9 RIU^–1, and detection limits reach 1.5 mRIU.Cross-sensitivity simulations for CO₂ and H₂O show that both interferents shift the TM resonance in the negativedirection, opposite to every target biomarker, so a sign comparisonon Δλ_TM separates interferent events from biomarkerevents before any further processing. The results show that the directionaloptical properties of BeS are themselves the selectivity mechanism,removing the need for a sensor array or chemical functionalization.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"4 8","pages":"2396–2408"},"PeriodicalIF":3.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148858955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controlling the Performance of Light-Activated Color-Changing Coatings Using Semiconductor Crystal Structure, Redox-Active Colorants, and Bulk Matrix Composition","authors":"Kaitlyn R. Flynn,&nbsp;Cassandra L. Martin,&nbsp;Kimberly A. Kiefer,&nbsp;Indya Taylor,&nbsp;Catherine L. Kappel,&nbsp;Luqmaan Shaikh,&nbsp;Kiersten O’Sullivan,&nbsp;Rachel C. Malampy,&nbsp;Daniel J. Wilson","doi":"10.1021/acsaom.6c00204","DOIUrl":"https://doi.org/10.1021/acsaom.6c00204","url":null,"abstract":"<p>Nonemissive display technologies, such as e-ink and e-paper,haveemerged as reconfigurable alternatives to single-use printed materialsthat become solid waste. These draw considerably less power than emissivedisplays but rely on traditional electronic circuitry and computercontrol to create displayed information. Reversible photochromic systems,in which displayed images are generated by patterned irradiation,enable fabrication of scalable, reversible media from single materialformulations, prepared as conformal thin films, without traditionalelectronic hardware. These systems can comprise combinations of redox-activechromophores and light-sensitive semiconductor particles formulatedin polymer matrices. The accessible colors and activation time scalesof reversible photoreduction of the embedded dyes, facilitated byultraviolet stimulation of proximal semiconductor particles, is controlledby the convergence of the optical (e.g., color), electrical (e.g.,band gap, redox potential) and physical (e.g., permeability) propertiesof the components of these formulations. To address this, we investigatethe catalytic behaviors of the two most abundant titanium dioxidepolymorphs, anatase and rutile, and their effect on the magnitude,rate, and reversibility of photoinduced color change of two redox-activecolorants, xanthommatin and methyl viologen. We demonstrate that theseformulations can be tuned to provide a diverse color range acrossa variety of activation time scales by controlling particle size,loading density, and particle–matrix interactions. We establishsemiconductor crystal structure and formulation design as criticaldeterminants of optical performance and provide a framework for engineeringtunable, low-energy optical materials for adaptive displays and reusablevisual communication technologies.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"4 8","pages":"2285–2301"},"PeriodicalIF":3.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148858956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tunable Band-Edge Magneto-Optical Response of Plasmonic Sn-Doped CdO Nanoparticles for Magnetoplasmonic Sensing","authors":"Misa Ueno,&nbsp;Hiroshi Yao","doi":"10.1021/acsaom.6c00288","DOIUrl":"https://doi.org/10.1021/acsaom.6c00288","url":null,"abstract":"<p>We report the successful synthesis of tin-doped cadmiumoxide (CdO)nanoparticles via solution-phase thermal decomposition of Cd(acac)₂ in the presence of a Sn(IV) compound at elevated temperatures.The obtained Sn-doped CdO nanoparticles have tunable plasmonic featureswith the peak position in the near-IR/mid-IR region, which is dependenton the nominal Sn doping level, ranging between 2.5 and 10%. Interestingly,in addition to the near-IR plasmon-based magnetic circular dichroism(MCD) signals, rather strong excitonic MCD responses are found inthe visible band-edge region, displaying a clear Burstein–Mossshift as a function of the Sn-doping level. Correlating the opticalabsorption spectra with the excitonic MCD leads to the effective massof electron (<em>m</em>*) of 0.45–0.5 <em>m</em>₀. The <em>m</em>* value can independentlybe estimated by the cyclotron shift energy of the near-IR magnetoplasmonicMCD responses, providing also the <em>m</em>* value of 0.45 <em>m</em>₀. The agreement of these <em>m</em>* values determined by two different analytical procedures provesthat the band-edge MCD responses are brought about by nonresonantcyclotron-carrier-induced exciton polarization in plasmonic Sn-dopedCdO nanoparticles.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"4 8","pages":"2326–2335"},"PeriodicalIF":3.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148858988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrafast Nonlinear Optical Response of Pb- and Zn/Li-Modified Germanate Glasses for All-Optical Switching","authors":"José L. Clabel Huamán,&nbsp;João V. P. Valverde,&nbsp;J. Chacaliaza-Ricaldi,&nbsp;Valmor R. Mastelaro,&nbsp;Leonardo de Boni,&nbsp;Lino Misoguti,&nbsp;C. R. Mendonça","doi":"10.1021/acsaom.6c00344","DOIUrl":"https://doi.org/10.1021/acsaom.6c00344","url":null,"abstract":"<p>Germanate glasses are emerging materials for nonlinearphotonicsowing to their broad IR transparency, dual GeO₄/GeO₆ coordination, and high refractive index. Two compositions,70GeO₂–10K₂O–20PbO (GKP) and 70GeO₂–10K₂O–10Li₂O–10ZnO(GKLZ), were synthesized to establish structure–property correlations.Both contain 10 mol % K₂O as a common alkali modifier,while Pb²⁺ (GKP) or Zn²⁺/Li⁺ (GKLZ)act as the main modifiers controlling structural and nonlinear behavior.FTIR and Raman confirmed Ge–O–Ge bending, ring-breathingmodes, and <em>Q</em>²/<em>Q</em>³ tetrahedra, whereas XPS O 1s spectra revealed low-binding-energyNBO/modifier-coordinated oxygen contributions and higher-binding-energyBO components, confirming Pb–O linkages in GKP and Zn–O/Li–Oenvironments in GKLZ. Band gap energies extracted from Tauc plotswere 3.67 eV (GKP) and 4.43 eV (GKLZ), while refractive indices at500 nm reached 1.74 and 1.67, respectively. The dispersion of thenonlinear refractive index (<em>n</em>₂), determinedvia nonlinear ellipse rotation (NER), ranges from (25 – 16) × 10^–20 m²/W for GKP and (18 – 13) × 10^–20 m²/W for GKLZ, with GKP exhibiting ∼1.3×higher values due to enhanced Pb²⁺ polarizability. TheSheik-Bahae framework indicates that predominant contributions tothe <em>n</em>₂ dispersion of the samples is 2PAand the Raman effect. Ultrafast optical Kerr gate measurements reveala response limited by the laser pulse (∼165 fs), confirmingthat <em>n</em>₂ of the samples originate froman ultrafast electronic nonlinearity. These combined features, high <em>n</em>₂, low nonlinear loss, and subpicosecond responsehighlight germanate glasses as promising platforms for ultrafast photonics,including all-optical switching and optical limiting.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"4 8","pages":"2433–2442"},"PeriodicalIF":3.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148858918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Indium-to-Tin Metal Modulation as a Strategy for Tuning Emission from Yellow to Orange in Zero-Dimensional Metal Halides","authors":"Suman S. Das,&nbsp;Chakali Srinivas,&nbsp;Rajanikanta Rana,&nbsp;Parameswar Krishnan Iyer,&nbsp;Saroj L. Samal","doi":"10.1021/acsaom.6c00309","DOIUrl":"https://doi.org/10.1021/acsaom.6c00309","url":null,"abstract":"<p>Metal-ion substitution offers an effective strategy fortailoringthe optical properties of low-dimensional organic–inorganichybrid metal halides (OIMHs). Herein, we demonstrate an indium-to-tinmetal modulation approach to systematically modulate the broadbandemission from yellow to orange in two zero-dimensional (0D) lead-freehybrid metal halides, (TMSO)₃InCl₆ and (TMSO)₂SnCl₆, incorporating the sulfur-based trimethylsulfoxonium(TMSO⁺) as an organic cation. Single-crystal X-ray diffraction(SCXRD) reveals that (TMSO)₃InCl₆ crystallizesin the triclinic <em>P</em>1̅ space group, whereas (TMSO)₂SnCl₆ adopts an orthorhombic <em>Pnnm</em> structure, both comprising isolated distorted [MCl₆]^{<em>n–</em>} octahedra surrounded by TMSO⁺ cations. Under ultraviolet excitation, the In-based compoundexhibits intense broadband yellow emission centered in the visibleregion with a full width at half-maximum (FWHM) of ∼142 nmand a high photoluminescence quantum yield (PLQY) of ∼63.9%,originating from a self-trapped exciton (STE) recombination. In contrast,replacing indium with tin shifts the emission to broadband orangewith a wider FWHM (∼165 nm) and a significantly lower PLQY(∼2%). The reduced luminescence efficiency of the Sn analogueis attributed to multiple STE states that facilitate nonradiativedecay. Further, the density functional theory calculations revealthat the excited-state polyhedral distortion is substantially greaterin (TMSO)₃InCl₆ than in (TMSO)₂SnCl₆, suggesting greater polyhedral localization, facilitatingSTE emission in the former compound. Hydrogen-bonding analysis revealsa greater extent of H-bonding in the In compound as compared to theSn analogue, leading to more polyhedral distortion and facilitatingefficient STE emission, corroborating the theoretical study. Thiswork establishes metal-ion variation as an effective strategy fortuning broadband emission and provides valuable insights into thestructure–property relationship governing STE luminescencein lead-free hybrid metal halides.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"4 8","pages":"2383–2395"},"PeriodicalIF":3.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148858959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphology and Structural Color in Coaxial Electrospun Liquid Crystal Fibers","authors":"Dong-Gue Kang,&nbsp;Minki Lee,&nbsp;Chinedum O. Osuji","doi":"10.1021/acsaom.6c00321","DOIUrl":"https://doi.org/10.1021/acsaom.6c00321","url":null,"abstract":"<p>Functional fibers with core–shellarchitecture hold promisesfor applications ranging from smart textiles to advanced stimuli-sensors.The performance of these materials is dictated by the structural uniformityand molecular alignment of the inner core, and there has been limitedprogress in developing experimental guidelines for producing uniformand stable fibers, mainly due to the difficulty in nondestructivevisualization of the internal core morphology. Despite the advancementsin coaxial liquid crystal (LC) fibers, still there remains a needfor a systematic nondestructive characterization of microscopic andmacroscopic core morphology. In this study, we address this gap byintroducing a strategic methodology that establishes LC fiber electrospinningtechniques by utilizing LCs as optically anisotropic and self-reportingcore materials. The intrinsic birefringence of the LC exhibits asvivid interference colors under polarized light microscopy, enablingdirect visualization of the core uniformity. The observed morphologicaltransitions are further rationalized by the Plateau–Rayleighinstability (PRI) model, providing a theoretical basis for understandingfiber formation dynamics. Based on this diagnostic capability, wesystematically established a regime map for categorizing the morphologicalevolution of the fibers as a function of processing parameters. Furthermore,we demonstrate structural color induced by a cholesteric liquid crystal(CLC) phase so that the coaxial fibers can serve as a macroscopicquality control indicator with the naked eye. The methodology andfindings presented here can offer practical guidelines for the fabricationof stable core–shell fibers with microscopic and macroscopicquality control.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"4 8","pages":"2409–2417"},"PeriodicalIF":3.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148858954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"P-Type Ni-Doped α-GaCrO3 (α-GaCrO3:Ni) Thin Films: Investigations of Structural, Optical, and Electronic Properties for Hole Transport Layer and Transparent Photodetector Applications","authors":"Prabhat Kumar Singh,&nbsp;Rishav Sharma,&nbsp;Himanshu Srivastava,&nbsp;Salahuddin Khan,&nbsp;Mangla Nand,&nbsp;Arijeet Das,&nbsp;Sanjay Kumar Rai,&nbsp;Rupesh Devan,&nbsp;Ravindra Jangir","doi":"10.1021/acsaom.6c00341","DOIUrl":"https://doi.org/10.1021/acsaom.6c00341","url":null,"abstract":"<p>Nickel-doped gallium chromium oxide (α-GaCrO₃:Ni)thin films were investigated for their potential application as holetransport layers (HTLs) in perovskite solar cells and as p-type transparentconducting oxide (TCO) in p–n junction-based photodetectors.Epitaxial α-GaCrO₃:Ni thin films were deposited onsapphire substrates by RF magnetron sputtering under varying oxygenpartial pressures, and their structural quality was determined byX-ray diffraction measurements. The film grown at 20% oxygen partialpressure exhibited lowest ω-scan full width at half maxima (fwhm)values of ∼330 arcsec for the out-of-plane (0006) diffractionpeak and ∼1855 arcsec for the in-plane (20–28) diffractionpeak. Optical characterization of the film revealed a large opticalband gap of 4.1 eV and exhibited an average transparency of more than70%. Photoelectron spectroscopy measurements confirmed a high ionizationenergy of 5.7 eV for the thin films, which is well aligned with theperovskite active layer having deep valence band maxima (VBM) likeMaPbBr₃ and CsPbBr₃. Atomic force microscopyand X-ray reflectivity analyses confirmed two-dimensional film growthwith smooth surfaces and interfaces. Transmission electron microscopyreveals a sharp and well-defined film–substrate interface.P-type conductivity of the thin film was confirmed by Seebeck measurements,while <em>I</em>–<em>V</em> measurement withplatinum (Pt) contacts demonstrated Ohmic behavior at room temperature.These findings suggest that its structural suitability for n-typetransparent conducting oxides (TCOs) integration and the alignmentof work function with the perovskite having deep VBM makes it a prominentcandidate as a HTL in solar cells and p-type TCO for p–n junctionphotodetectors.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"4 8","pages":"2443–2453"},"PeriodicalIF":3.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148858970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}