http://dspace.dtu.ac.in:8080/jspui/handle/123456789/31 2026-05-07T22:20:31Z http://dspace.dtu.ac.in:8080/jspui/handle/repository/22703 Title: STUDIES ON RARE EARTH DOPED LUMINESCENT MATERIALS FOR APPLICATIONS IN GENERAL ILLUMINATION AND BIO-PHOTONICS Authors: BAJAJ, RAJAT; RAO, A. S. (SUPERVISOR); PRAKASH, G. VIJAYA (CO-SUPERVISOR) Abstract: Research in the field of luminescent materials doped with rare earth (RE) and transition metal (TM) ions has taken giant strides due to the rapid development of technologies such as solid-state lighting and other display technologies. RE ions doped glassy materials also find applications in lasers, optoelectronic devices, and civil-military applications such as infrared detectors, infrared fairings, nuclear imaging, and detection. Photo luminescent glass applies these distinctive properties to photonics, lighting, and photovoltaics by applying Downconversion light from UV to visible or near-infrared (NIR) light, and it is suitable for display devices, smart windows, lasers, and optical fibers & w-LEDs, among many other applications. RE doped glasses useful for optoelectronics devices have been fabricated and characterized by many researchers because of their high transparency, low production cost, ease of shaping, and relatively high thermal stability. Rare earth activated glasses, and nanophosphor are important groups of engineering materials that can be used in a wide range of multifunctional and industrial applications. The advantages of glasses and glass ceramics have attracted a lot of attention. Inorganic glasses, which belong to the unique family of amorphous solid-state materials, are usually thermally stable and form over a wide range of glass-former concentrations. Since Snitzer first demonstrated the laser action of Nd3+ ions in barium crown glass in 1961, a great deal of work has been done on rare-Earth-doped glasses for solid-state lighting (SSL) applications, broadband optical amplifiers, up-conversion luminescence temperature sensors, and near-IR STUDIES ON RARE EARTH DOPED LUMINESCENT MATERIALS FOR APPLICATIONS IN GENERAL ILLUMINATION AND BIO-PHOTONICS vii lasers. Additionally, optical fibers that emitted infrared light were made using a variety of precursor glasses. In the current work, we have created a good glassy system (using the melt quench method) called alkali zinc alumino borosilicate (AZABS) glass doped with varying concentrations of europium ions. We have characterized them spectroscopically to gain insight into their suitability for general illumination such as w-LEDs and other related SSL device applications, all against the backdrop of the various scientific patronages of chemical species like H3BO3, SiO2, Al2O3, ZnO, and Na2CO3. Also, the spectral properties of RE doped chlorides, oxides, fluorides and phosphate have been studied extensively to understand their suitability as potential luminescent applications. However, most of the systems are sensitive to moisture and thus are not quite suitable for bio labeling except the fluoride compounds with a formula such as AREF4 (A = alkali, RE = rare earth F = Fluoride) [38,39]. Among AREF4 host lattices, KREF4 (K stands for potassium) especially have attracted much more attention because of the high reflective index and low phonon energy that make them excellent host matrix for both DS as well as UC processes For the current thesis project, the rare earth-doped luminous material's industrial and multipurpose uses are chosen based on the previously described benefits. Enhancing the luminous qualities of rare earth ion-doped glasses and nanophosphors for use in biomedical and general illumination applications is the main goal of the research. Several chapters are meeting the research's objectives. Each chapter is meant to be read independently. Chapter 1: A clearer introduction, the reason for the problem, the motivation for the research, and a review of recent literature are all included in the first chapter. This chapter starts with a brief introduction, the origin of the problem, the motivation of the research work, and an overview of the current literature. This chapter provides an introduction to different types of glasses and nanophosphors, the components involved in their formation, and their specific viii properties. Furthermore, the importance of borosilicate glasses and nanophosphor are discussed in detail. Based on the characteristics required for glass host, 35B2O3.20SiO2.15Al2O3.15ZnO. -15Na2CO3 glass composition selected to synthesize, transparent, thermally mechanically stable glass with exceptional photonic properties, which can directly be applicable in general illumination. This approach has involved a thorough exploration of the properties of the many chemical components present in the host glass. The usefulness of RE ions doped in glasses for use in photonic devices has been studied further. Also, discussed the Eu doped KYF4 (Potassium Yttrium Fluoride) nanophosphors as promising host material for biomedical application. Chapter 2: The experimental process used for producing RE-doped glasses and nanophosphor and the methods for evaluating their luminous properties are the main topics of the second chapter. There is also a detailed discussion of the melt-quench process, which is used to create as-prepared glasses. This chapter describes the use of many sophisticated experimental techniques, such as X-ray diffraction (XRD), UV-VIS spectrophotometer, Temperature Dependent PL (TDPL) Spectroscopy, PL Decay Spectroscopy, SEM, and Up-conversion processes, to study various properties, including thermal, structural, photoluminescent, and colorimetric properties. Chapter 3: In this chapter, Dy3+ doped Alkali Zinc Alumino Borosilicate (AZABS) glasses have been prepared via melt quenching technique. A series of AZABS glasses of varying concentrations of dysprosium (Dy3+) (0.1 mol% -2.5 mol%) was prepared. It was found that under UV excitation, 0.5 mol% Dy3+ doped glass exhibited maximum luminescence intensity. Subsequent photoluminescence studies like emission/excitation spectra, temperature dependent photoluminescence and decay kinetics were also performed. Dexter theory was applied to study the energy transfer mechanism between the dopant ions in the glass matrix. Positive and ix encouraging results from all the photoluminescence studies for Dy3+ doped AZABS glasses confirm that these as-prepared glasses can be used as prospective materials in general illumination. [Part of this work has been published in Journal of Materials Science: Materials in Electronic, 33 (2022) 4782–4793 (Impact Factor = 2.8)] Chapter 4: Samarium (Sm3+) ions doped AZABS glasses were synthesized via quick melt quench technique. Various spectroscopic studies like optical absorption, photoluminescence (PL) emission, PL excitation, temperature-dependent PL and PL decay kinetics were performed on the as prepared glass system. Under 402 nm excitation, three sharp bands at wavelengths 563, 599 and 645 nm corresponding to transitions 4G5/2 → 6H5/2, 6H7/2 and 6H9/2 respectively can be seen in the PL emission spectra. The 0.25 mol% Sm3+ glass has the highest intensity for these emissions. The lanthanide interaction in the glass matrix is dipole-dipole in nature as was proven from Dexter’s analysis. The direct bandgap of 0.25 mol% Sm3+ doped AZABS glass was calculated to be 2.88 eV. The lifetimes of the as prepared glasses range from 1.93 ms for the lowest concentration of Sm3+ to 0.75 ms for the highest. From temperature dependent PL studies, the activation energy for 0.25 mol% Sm3+ doped AZABS glass was found to be 0.19 eV which shows high thermal stability of this glass. We propose to utilize these Sm3+ doped AZABS glasses for general illumination such as w-LEDs and solid-state lighting (SSL) applications. [Part of this work has been published in Luminescence 28 (2023), 428-436, (Impact Factor = 3.2)] Chapter 5: In this chapter we discuss the synthesis of thermally stable borosilicate glasses doped with europium ions having chemical composition 35B2O3.20SiO2.(15-x)Al2O3.15ZnO. 15Na2CO3.xEu2O3 (x = 0.5 to 2.5 mol%) using melt quench process. A broad hump without any sharp peaks observed in the XRD spectrum recorded for an undoped glass confirm its glassy x nature. The DSC & TGA has been conducted on an undoped glass to understand thermal stability and aggregate weight loss. The absorption spectral features recorded for the as prepared glasses are used to estimate optical band gap. In the process of understanding the effective usage of the as prepared glasses in visible red photonic device applications, the spectral features such as photoluminescence (PL) excitation, PL emission and PL decay were recorded and analyzed. Under 393 nm sharp excitation, all the glass samples are showing red emission corresponds to 5D0 → 7F2 transition (612 nm) and whose intensity continuously increasing with Eu3+ ion concentration up to 2.5 mol%. The red to orange color ratio (R/O) estimated from the recorded PL spectral features varies from 3.62 to 3.92 within the variation limits of Eu3+ ions from 0.5 to 2.5 mol% indicates relatively low symmetry around Eu3+ ions in the as prepared glasses. Relatively higher R/O ratio also reveals that the nature of bonding between Eu3+ ions and the surrounding ligands as covalent. The Judd-Ofelt theory has been applied to the emission spectral features to understand the nature of bonding between the doped RE ion and its surrounding ligands along with the radiative properties of the doped RE ion. Activation energy (0.175 eV) and percentage loss (82%) in PL intensity estimated for 2.5 mol% of Eu3+ ions through temperature dependent PL (TDPL) studies reveal the superiority in thermal stability of the as prepared glasses. The PL, TDPL, PL decay studies conducted along with CIE coordinates estimated allows us to contemplate that, the as prepared glasses are quite useful in fabricating thermally stable visible red photonic devices. [Part of this work has been communicated in Journal of Non-Crystalline Solids 575 (2022) 121184 (Impact Factor = 3.2)] Chapter 6: This chapter deals with the synthesis of cubic phase KYF4:Eu3+ nanophosphors via wet chemical route. Morphological studies such as XRD, SEM and EDAX mapping were done to ascertain shape, size and composition of the as prepared nanophosphors. Debye Scherrer formula applied to the XRD spectral features of the as prepared nanophosphors reveals the xi average size in the range 3 - 4 nm. The JCPDS data analysis for KYF4:Eu3+ nanophosphors confirm cubic structure with lattice constant a = b = c = 5.448Å and α = β = γ = 90°. The SEM image mapping clearly demonstrates the uniform distribution of all the constituent elements such as potassium, yttrium, fluorine and europium. Up-conversion (UC) studies carried out using 800 nm spitfire femtosecond laser produces peaks at 576, 590, 612, 650, 700 nm pertaining to the transitions 5D0 → 7Fj (J = 0, 1, 2, 3, 4) respectively. In addition to this, three higher order peaks are also observed at 523 531, 552 nm pertaining to 5D1 → 7Fj (J = 0, 1, 2) transitions respectively. Down-shifting (DS) studies under 393 nm and 405 nm excitation were also recorded to understand the utility of the as prepared phosphors for lighting applications. These nanophosphors are capable of emitting visible emissions under UV/NIR excitations. The powder dependence studies conducted on UC and DS reveal the excitation process as two photons and single photon respectively. DS temperature dependent PL spectral revels good thermal stability for the as prepared phosphor. The interesting results obtained allow us to contemplate that the as prepared KYF4:Eu3+ nanophosphors are useful for bio-imaging (through UC) as well as lighting applications (through DS). [Part of this work has been published in Journal of Alloys and Compounds, 885 (2021), 160893, (Impact Factor = 5.8)] Chapter 7: An overview of the overall study effort and the particular conclusions drawn from the data are presented in sixth chapter of this dissertation. This chapter also looks at future directions and social impact for this study and how it could be used to inform future research directions. 2025-05-01T00:00:00Z http://dspace.dtu.ac.in:8080/jspui/handle/repository/22698 Title: DESIGN AND DEVELOPMENT OF STRAINED CHANNEL ENGINEERED MULTIGATE FERROELECTRIC BASED FINFET FOR ANALOG AND CIRCUIT APPLICATIONS Authors: VERMA, KAJAL; CHAUJAR, RISHU (SUPERVISOR) Abstract: The growing demand for low-power, high-performance electronics, smart devices, and logic-inmemory systems has pushed Complementary Metal Oxide Semiconductor (CMOS) scaling to its physical limits, where challenges such as gate leakage, Drain Induced Barrier Lowering (DIBL), and dopant variability hinder further advancements. Ferroelectric FinFETs (FeFinFETs) address these issues by integrating ferroelectric materials with FinFETs, enabling strong electrostatic control and polarization-driven charge modulation to suppress short channel effects (SCEs) and enhance device performance. Building on this, the present work investigates a strained Vertically Stacked FeFinFET (VS-FeFinFET) architecture, incorporating silicon on insulator (SOI) based substrate engineering to improve energy efficiency and reduce parasitics, and strained Si/SiGe heterostructure tri-layered channel system for enhancing carrier transport. These combined strategies culminate in the development of the Vertically Stacked Heterostructure on Insulator FeFinFET (VS-HOIFeFinFET), offering superior scalability and robust device performance for next-generation modern applications. Initially, the extensive analysis is done to optimize VS-HOI-FeFinFET and on comparison with baseline FeFinFET, VS-HOI-FeFinFET is found to show remarkable improvements in terms of various measured parameters such as 97.84% reduction in leakage current (Iof f ) and 35.98% increment in drain current (Ion), which consequently results the switching ratio to increase around 61 times along with substantial improvement in threshold voltage and subthreshold swing. Further, four multi-material gate stack configurations such as C1(SiO2+Al2O3), C2(SiO2+HfO2), C3(Al2O3), ix KAJAL VERMA and C4(Al2O3+HfO2), are analysed and with the sequential enhancement in static and analog performance, C4 showcased upto 5 times improvement in switching ratio, ∼41% reduction in DIBL, and ∼58% better quality factor along with achieving remarkable improvements in early voltage, intrinsic gain, device efficiency, output resistance, and conductance, highlighting suitability for analog applications. In addition, the optimization with variation in mole fraction, fin geometry and oxide-ferroelectric layer thickness is proved as critical levers for tuning the electrostatics of the device to achieve lower leakage, improved switching ratio and enhanced gate control, thereby ensuring energy-efficient, reliable, and scalable device design for improved performance. RF analysis revealed three times improvement in gain frequency product (GFP) and gain transconductance frequency product (GTFP), along with 16% reduction in unity gain cut-off frequency, enabling high-frequency amplification with minimized noise distortion. Collectively, these optimizations provide a robust design strategy for achieving energy-efficient, reliable, and high-performance FeFinFET tailored for future high performance analog and RF applications. Furthermore, VS-FeFinFET is explored for improved reliability under the influence of interfacial trap charges (ITCs) at the semiconductor/oxide interface. Gate engineering has also been incorporated to form hetero dielectric vertically stacked ferroelectric based FinFET (HD-VS-FeFinFET), which results to 91.48% reduction in Iof f and 13 times increment in switching ratio along with improvement in quality factor by 46.01%, transconductance (gm) by 32.77%, and device efficiency (TGF) by 26.54% with negligible variations due to ITCs as compared to VS-FeFinFET. Various linearity and harmonic parameters also improved and showed negligible average variations like 4.72% (177.15%) in VIP2 and 6.52% (25.3%) in 1-dB compression point for HD-VS-FeFinFET (VS-FeFinFET) against different ITCs polarity making it more reliable for low power microwave and distortionless wireless communication applications. Further, logic circuit application of HDVS-FeFinFET based CMOS inverter has been analysed and it shows improvement by 17.9% in transition range, 51.67% in voltage gain along with minimal ITCs induced average variation of 3.66% (15.88%) in noise margin for HD-VS-FeFinFET(VS-FeFinFET) based circuit, showcasing its enhanced reliability at circuit level. Thereafter, a detailed investigation is carried out to analyse the coupled effects of thermal-trap dynamics on the performance of HD-VS-FeFinFET device along with enhancing its applicability as CMOS inverter in varying operating environments. Temperature affectability reveals that HDx Delhi Technological University, Delhi-42 KAJAL VERMA VS-FeFinFET exhibits better reliability with less average variations against ITCs at all operating temperatures such as 10.65% in Iof f and 11.39% in output resistance (Rout) at 300K which further decreases to 8.13% in Iof f and 7.76% in Rout at 400K in contrast to huge variation shown by VSFeFinFET like 82.05% in Iof f and 43.10% in Rout at 300K along with 59.35% in Iof f and 29.86% in Rout at 400K. Further, the analysis done at various ITCs densities and polarities reveals that, at higher donor trap charge density of 1013 cm−2 , the device performance alters significantly for VS-FeFinFET with degradation in Iof f by 552 times in comparison to HD-VS-FeFinFET which degrades only by 2.52 times, thus making it more reliable under varying environmental conditions. Subsequently, HD-VS-FeFinFET based CMOS inverter demonstrates high reliability and robustness under combined effects of temperature variation and ITCs with only 6.8% reduction in noise margin when temperature rises from 300K to 400K along with negligible variations at all operating temperatures, exhibiting its improved immunity against ITCs, making it a reliable choice for digital circuits in varying operating environments. Later, a comprehensive investigation of ferroelectric HfO2 based devices is presented, encompassing both material-level and device-level analyses. At the device level, the impact of various doped ferroelectric materials on the transfer characteristics of HD-VS-FeFinFET is studied, highlighting dopant-driven modulation of the performance parameters with enhancement in Ion by 24%, gm by 29% and TGF by 10.8% for silicon doped HfO2 over lanthanum doped HfO2 as ferroelectric layer. Subsequently, Density Functional Theory (DFT) simulations are performed to examine the structural and electronic properties of undoped HfO2 and its doped variants using Gadolinium (Gd) and Silicon (Si), which are found to be two best performing ferroelectric materials at the device level. The influence of different dopants material on band structure and projected density of states are analyzed to evaluate their suitability for ferroelectric applications. The influence of increasing dopants concentration for silicon doped HfO2 is also studied at DFT level. Further, self-heating effects (SHE) are critically examined in HD-VS-FeFinFET structure across varying biasing voltages and ambient temperatures. The analysis reveals influence on analog parameters along with lattice temperature contour evolution due to SHE, emphasizing its impact on device reliability. Further, the output characteristics also show alteration in drain current by 33.3% due to SHE which decreases to 0.03% with reduction in Vgs from 0.6V to 0.2V. Finally, CMOS inverter circuit utilizing these advanced technologies is analyzed in terms of switching characteristics under different biasing xi Delhi Technological University, Delhi-42 KAJAL VERMA voltages and thermal conditions. Key performance metrics such as switching current, propagation delay, rise time, and fall time are also evaluated to assess circuit-level implications of material and device-level effects. Along with this, circuit level analysis of HD-VS-FeFinFET based NAND logic gate circuit is also examined. Thus, the integrated multi-scale analysis provides a holistic understanding of material doping, thermal effects, and circuit performance, establishing a pathway for the optimized design of ferroelectric-based next-generation systems in advanced low-power, high-speed electronic applications. In conclusion, HD-VS-FeFinFET emerges as a highly promising device for next-generation lowpower and high-performance analog and circuit applications. Its remarkable switching ratio, minimal leakage, strong resilience against thermal-trap variations, coupled with superior static, analog, and RF characteristics along with enhanced switching dynamics and improved inverter noise immunity, position it as a robust and energy-efficient solution for future CMOS technologies. 2026-04-01T00:00:00Z http://dspace.dtu.ac.in:8080/jspui/handle/repository/22697 Title: MODELING AND DESIGN OF SPECIALTY OPTICAL FIBERS AND WAVEGUIDES FOR SUPERCONTINUUM GENERATION Authors: TOMER, DRISHTI SINGH; KUMAR, AJEET (SUPERVISOR) Abstract: This thesis focuses on the modeling and design of specialty optical fibers and waveguides for supercontinuum generation, targeting applications across diverse domains of nonlinear optics and photonic systems. By employing highly nonlinear materials such as silica, chalcogenides, and organic liquids, these designs aim to generate broad supercontinuum spectra spanning from the visible to the mid-infrared. The approach emphasizes short interaction lengths and low input peak powers, while maintaining high temporal coherence to maximize bandwidth and ensure spectral flatness. These specialty optical fibers and waveguides find applications in various fields like biomedical, military and sensing technologies. Supercontinum generation is the process where amalgamation of various nonlinear phenomena including stimulated Raman scattering, self-phase modulation, cross-phase modulation, and fourwave mixing takes place. They work together on an intense pump beam, leading to a significant amount of spectral broadening compared to the original pump beam in an optical fiber. The generated supercontinuum sources can be used to discern chemicals, inspect food quality, detect explosives and hazardous gases, ulcer and cancer diagnosis, frequency comb generation, optical imaging, and optical coherence tomography. In this thesis, we have numerically designed photonic crystal fibers and waveguides for supercontinuum generation across the visible to mid-infrared spectrum using the finite element method. By optimizing core and cladding geometries and adjusting core – cladding materials, we have minimized dispersion at the pump wavelength. The impact of input peak power, pulse width, fiber length and coherence on supercontinuum broadening has been numerically analyzed. The proposed waveguide structure with a parabolic core, implemented in a chalcogenide glass results in the generation of a mid-IR supercontinuum spectrum when pumped in the normal dispersion region. This design is crucial as the fabricated rectangular waveguide does not remain rectangular after laser post processing but becomes similar to the proposed parabolic design. Another chalcogenide based graded-index hybrid cladding photonic crystal fiber is suitable for the generation of an ultra-broadband supercontinuum spectrum from 1 µm to 11 µm in MIR domain when pumped with the peak power of 0.75 kW at 5µm with 50 fs pulse width. We have also proposed liquid-infiltrated photonic crystal fibers to enhance the nonlinearity of silica fibers, enabling the generation of a highly coherent broadband supercontinuum. Ethanol based photonic crystal fiber results in a flat-top dispersion profile with a low peak power of 0.55kW at a pump wavelength of 1.55 μm. Another photonic crystal fiber design infiltrated with nitrobenzene results ix in a spectrum ranging from 1.3 μm to 2.0 μm for the circular design (#C), from 0.9 μm to 2.3 μm for the elliptical x-polarised design (#EX) and from 1.0 μm to 2.4 μm for the elliptical y-polarised design (#EY). For dual infiltrated photonic crystal fibers we have a broadband supercontinuum spanning from 1.3 µm – 1.8 µm for design #A, 1.0 µm – 2.4 µm for design #B, 1.2 µm – 2.5 µm for design #C and 0.9 µm – 2.5 µm for design #D is obtained by using a fiber length of 4 mm to 8 mm with 50 fs secant laser pulse source and pump power of 600 W to 800 W. The suggested waveguide and photonic crystal fiber designs can be employed for various critical applications involving detection of explosives, various gases, cancers, ulcers and enhanced monitoring systems for food quality detection. 2026-03-01T00:00:00Z http://dspace.dtu.ac.in:8080/jspui/handle/repository/22682 Title: SYNTHESIS AND INVESTIGATION OF TRANSITION METAL DICHALCOGENIDES: NANOSTRUCTURES AND THEIR APPLICATIONS Authors: ANEESHA Abstract: Transition-metal dichalcogenide (TMD) quantum dots (QDs) represent a rapidly advancing class of nanomaterials distinguished by tunable photoluminescence (PL), high surface reactivity, chemical stability, and biocompatibility, yet achieving water- stable QDs with strong emission remains challenging. This thesis systematically examines the hydrothermal synthesis of WS2 and MoSe2 QDs and correlates their physicochemical properties with optical behavior to develop high-performance fluorescent probes for detecting industrial, environmental, and pharmaceutical contaminants. Alkaline-synthesized WS2 QDs (pH ≈ 11) resolved the instability associated with acidic exfoliation, producing highly dispersible, blue-emitting QDs with multiexponential lifetimes and strong structural stability. These QDs were comprehensively characterized using XRD, FTIR and HR-TEM, while their optical responses were evaluated through steady-state and time-resolved spectroscopy, collectively confirming their crystalline integrity, defect-mediated emissive states and robust aqueous stability. The WS2 QDs demonstrated exceptional sensitivity toward hydrogen peroxide (0.33 nM–594 μM, LoD 1.7×10-6 M) through reversible redox cycling between W(IV) and W(VI), enabling nearly complete signal recovery across multiple cycles. Complementarily, hydrothermally prepared MoSe₂ QDs characterized by strong 260 nm absorption and blue excitation-dependent emission served as highly sensitive probes for 2,4,6-trinitrophenol (TNP), showing linear Stern–Volmer behaviour (3.3–99 nM) and an LoD of 1.43 nM dominated by the inner filter effect. Together, these findings highlight the tunability and responsiveness of TMD QDs toward oxidative and nitroaromatic pollutants. Further extending their sensing versatility, WS₂ QDs were applied for detecting heavy-metal ions and pharmaceutical contaminants. For Cr6+, the QDs exhibited strong and reversible PL quenching driven primarily by static surface complexation, supported by XPS evidence of partial oxidation of W and S atoms. The platform delivered ultralow detection limits (39.5–154 pM across different water matrices), a broad linear range (0.66–660 nM), and excellent recyclability over more than 18 redox cycles, establishing it as one of the most sensitive WS2-based Cr6+ sensors to date. WS2 QDs also enabled sensitive, label-free detection of Vitamin B12 via a static-dominated ix ANEESHA mechanism (0.33–565 nM range, 555 pM LoD), and amoxicillin via combined static– dynamic quenching supported by FTIR-verified adsorption and minor lifetime changes (0.33–607 nM, 1.24 nM LoD). Collectively, this research demonstrates that hydrothermally synthesized WS2 and MoSe2 QDs form a robust, regenerable, and environmentally benign sensing platform capable of detecting oxidants, metals, nitroaromatics, vitamins, and antibiotics. The study provides crucial insight into structure, property and function relationships in TMD QDs, and establishes their strong potential for real-sample monitoring, multimodal sensing, catalytic remediation, and emerging biophotonic applications. 2025-11-01T00:00:00Z