arXiv subjects

Lukasz Marciniak

Publications and source records attributed to Lukasz Marciniak.

11 recordsLinked to original sources

arXiv2026

Re4+ Luminescence as a Highly Sensitive Alternative to Ruby for Optical Pressure Sensing

Luminescence-based remote pressure sensing provides a powerful approach for pressure determination under conditions where conventional contact methods are difficult to implement. Although ruby remains the undisputed gold standard among luminescent pressure indicators, its relatively low pressure sensitivity and susceptibility to temperature variations represent important limitations. Therefore, in this work, Cs2HfCl6:Re4+ is proposed as an alternative luminescent pressure indicator exhibiting a 15-fold higher pressure sensitivity (6.93 nm GPa-1) than ruby while maintaining a comparable thermal sensitivity, making it a particularly attractive material for optical manometry. Furthermore, Cs2HfCl6:Re4+ enables ratiometric pressure readout, providing a high relative pressure sensitivity reaching 175.1% GPa-1. To the best of our knowledge, this work represents the first demonstration of Re4+ luminescence for pressure sensing, introducing a new class of luminescent pressure indicators and opening new opportunities for the development of highly sensitive optical manometers based on Re4+-activated materials.

cond-mat.mtrl-sci↗

arXiv2025

Structural Phase Transition and Cooperative Luminescence in K3Yb(PO4)2:Eu3+ for Multimodal Down-shifting and Up-converting Luminescence Thermometry

To develop a more universal luminescent thermometer that provides both high relative sensitivity and the ability to measure temperature across different spectral ranges and excitation wavelengths, the K3Yb(PO4)2:Eu3+ system was proposed in this work. It was demonstrated that this material undergoes a structural phase transition from the monoclinic to the hexagonal phase above 450 K. This transition enabled the construction of a ratiometric, phase-transition-based thermometer utilizing the luminescence intensity ratio of Stark lines of Eu3+ and Yb3+ ions, which exhibit SRmax values of 4.2% K^-1 and 1.15% K^-1, respectively. Moreover, increasing the Eu3+ ion concentration was shown to raise the phase transition temperature, thereby shifting the thermal operating range of both luminescent thermometers. Under 980 nm excitation, K3Yb(PO4)2:Eu3+ exhibits both cooperative luminescence from Yb3+ pairs and up-conversion emission from Eu3+ ions. Increasing the Eu3+ concentration enhances the Eu3+ luminescence intensity relative to the cooperative luminescence of Yb3+ pairs, resulting in a change in the emitted light color. The difference in the thermal quenching behavior of these two signals further enabled the development of a ratiometric thermometer with SRmax = 0.58% K^-1. These findings identify K3Yb(PO4)3:Eu3+ as a promising candidate for multimodal temperature sensing.

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arXiv2025

Constructing a bifunctional platform based on Mn2+-doped Mg2Y8(SiO4)6O2 phosphors for multi-parameter optical thermometry and manometry

Series of the Mn2+-doped Mg2Y8(SiO4)6O2 phosphors were synthesized. Upon excitation at 408 nm, these phosphors exhibited intense orange emission originating from Mn2+, with concentration quenching observed beyond x = 0.07, and they also demonstrated excellent thermal stability. For optical thermometry, two independent parameters, emission band centroid (λ) and lifetime, were employed as thermal indicators, yielding sensitivities of dλ/dT = 0.053 nm K-1 and SR = 0.86% K-1, respectively. High-pressure in-situ X-ray diffraction revealed that the phosphors retained structural integrity under compression, accompanied by a progressive lattice contraction. With increasing pressure (0.13-10.89 GPa), a spectral red-shift was observed, corresponding to a pressure sensitivity of dλ/dp = 4.75 nm GPa-1. Additionally, pressure-dependent shifts in color coordinates allowed the development of a colorimetric manometric response, achieving a relative sensitivity of 3.27% GPa-1. Remarkably, the pressure-induced spectral shift of Mn2+ emission, characterized by low thermal cross-sensitivity, enabled a highly reliable ratiometric manometric strategy, with a relative sensitivity of 72% GPa-1. Notably, the system delivered the highest TIMF reported to date above 3 GPa, peaking at 1940 K GPa-1 at 7 GPa. These results position Mn2+-doped Mg2Y8(SiO4)6O2 phosphors as a highly promising bifunctional material for next-generation, multi-parameter optical sensing applications under extreme conditions.

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arXiv2025

Unlocking Dynamic Luminescent Mapping of pH with Sustainable Lignin-Derived Carbon Dots with Multimodal Readout Capacity

In this work, we demonstrate the use of CQDs synthesized from lignin - currently one of the most abundant and underutilized by-products of paper and pulp production - for advanced pH monitoring applications. The presented approach integrates green chemistry principles with an operator-friendly, low-cost, and practical solution for spatial and temporal pH measurement. CQDs functionalized with m-aminophenylboronic acid enable highly sensitive and reversible pH readouts through two complementary mechanisms: ratiometric monitoring of emission band intensities, and direct visual observation of colorimetric changes reflected in the CIE1931 chromaticity coordinates. The system achieves maximal sensitivities of 137 percent per pH unit and 49.5 percent per pH unit, respectively, while simultaneously maintaining high measurement resolution and full reproducibility of the readouts, placing it among the most effective CQD-based pH sensors reported to date. Here, we demonstrate the capability of 2D luminescent imaging of pH distributions, allowing for both spatially resolved and time-resolved monitoring. Employing just an excitation source, a digital camera or smartphone, and RGB channel analysis, the setup eliminates the necessity for specialized filters or sophisticated instrumentation. The combination of multimodal readout strategies with the capacity for large-area visualization establishes lignin-derived CQDs as a sustainable and practical platform for pH sensing. By simultaneously addressing the challenges of waste valorization and the demand for innovative sensing technologies, this solution fulfills the requirements of both environmentally responsible material design and next-generation pH sensor development.

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arXiv2025

From the up-converting multimodal luminescent thermometer to ratiometric visual power density meter based on Er3+,Yb3+ emission

This study demonstrates that thermally induced variations in the spectroscopic properties of Na3Sc2(PO4)3:Er3+, Yb3+ can be effectively harnessed for multimodal remote temperature sensing. As shown, Na3Sc2(PO4)3:Er3+, Yb3+ supports multiple ratiometric sensing modes based on the intensity ratios of (i) 2H11/2 -> 4I15/2 and 4S3/2 -> 4I15/2; (ii) 2H9/2 -> 4I13/2 and 4S3/2 -> 4I15/2; and (iii) green-to-red emission intensity ratio, achieving maximum relative sensitivities of 2.8% K-1, 3% K-1, and 1.8% K-1, respectively. The synergy between thermal changes observed in the green-to-red emission intensity ratio of Er3+ ions, combined with the efficient optical heating of Na3Sc2(PO4)3:Er3+, Yb3+ at elevated Yb3+ concentrations enables the development of a visual optical power density sensor, exhibiting relative sensitivities of SRx = 1.0% W-1 cm2 and SRy = 0.9% W-1 cm2 at 15 W cm-2 when quantified using CIE 1931 chromaticity coordinates. To the best of our knowledge, this is the first report of a visual luminescent optical power density sensor. Furthermore, it was demonstrated that Na3Sc2(PO4)3:Er3+, Yb3+ can be successfully applied for two-dimensional imaging of optical power density, thereby enabling spatial visualization of power distribution within an illuminated field.

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arXiv2025

Bridging Two Dimensions: Luminescent Sensors at the Intersection of Temperature and Pressure

Luminescence thermometry and manometry are exponentially growing areas dealing with the optical detection of temperature and pressure, respectively, being appealing alternatives for conventional thermometers and manometers. The main benefit of luminescent thermometers and manometers is a possibility of remote temperature and/or pressure monitoring, in contrast to conventional gauges. Moreover, the use of luminescent nanoparticles as temperature/pressure sensors allow detection in micron- and nano-sized areas, previously inaccessible for conventional gauges. Therefore, the combination of both functionalities in a single material is highly appealing, as has been shown in a growing number of reports in the last years. Moreover, the bifunctional pressure and temperature sensors, operating with multiple independent spectroscopic parameters, allow simultaneous and distinct pressure and temperature readouts. However, the development of such truly bifunctional and reliable sensors is very challenging and rarely reported. This review summarizes the current status in the field, focusing on the sensing strategy and the selection of optically active sensor materials appropriate for a given application, including their sensitivity, spectral range of interest and pressure/temperature (in)dependence.

cond-mat.mtrl-sci↗

arXiv2025

Modulating Thermometric Performance via Dopant Concentration and Morphology in Luminescence Thermometer Exhibiting Dual Structural Phase Transitions

Expanding the operational range of luminescent thermometers that utilize thermally induced structural phase transitions in lanthanide-doped materials necessitates the exploration of novel host matrices with diverse thermal behaviors. In line with this objective, the present study offers a comprehensive analysis of the temperature-dependent spectroscopic properties of Li3Sc2(PO4)3:Eu3+. The findings reveal that the studied material undergoes two reversible phase transitions: γLT - α/\b{eta} phase transition at approximately 160 K, followed by an \b{eta} HT transition around 550 K. These transitions are evidenced by notable alterations in the emission spectra and luminescence decay kinetics of Eu3+ ions. By employing an appropriate luminescence intensity ratio, the sensitivity was determined to be 7.8 % K-1 at 160 K for 0.1%Eu3+ and 0.65 % K-1 at 550 K for 0.5%Eu3+. Furthermore, the study demonstrates that the phase transition temperature in Li3Sc2(PO4)3:Eu3+ can be modulated through variations in dopant ion concentration and annealing conditions, which in turn influence the material's morphology. These strategies enable the fine-tuning of thermometric performance in phase transition-based luminescent thermometers. To the best of our knowledge, this represents the first report in the literature of a luminescent thermometer exhibiting dual thermal operating ranges.

cond-mat.mtrl-sci↗

arXiv2025

Exploring the Interplay Between Formation Mechanisms and Luminescence of Lignin Carbon Quantum Dots from Spruce Biomass

This study investigates the intricate relationship between the formation mechanisms and luminescent properties of lignin-derived carbon quantum dots (LG-CQDs) synthesized from spruce biomass by hydrothermal treatment. A comprehensive understanding of LG-CQD structure and its photoluminescence requires insights into the native architecture of lignin and the distribution of its acidolysis-derived fragments. Research showed how these lignin-derived units interact with dopant molecules in three different approaches during synthesis, contributing to core and surface structures that govern the optical behavior. Our findings reveal a clear correlation between structural features and luminescent properties, emphasizing the role of surface chemistry in tuning emission characteristics. These insights provide a foundation for the rational design of LG-CQDs with tailored luminescent properties, advancing their potential applications in sustainable optoelectronics, sensing, and bioimaging.

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arXiv2025

Luminescent Platform for Thermal Sensing and Imaging Based on Structural Phase-Transition

The remarkable sensitivity of the luminescent properties of Eu3+ ions to structural changes in host materials has been well-explored for years. However, the application of this feature of Eu3+ in materials exhibiting thermally induced structural phase transitions for the development of luminescent thermometers has only recently been proposed. The narrow operating range of such thermometers necessitates the exploration of new host materials. In response to this demand, this study carefully analyzes the spectroscopic properties of X as a function of temperature and dopant ion concentration. As demonstrated, X undergoes a phase transition from a low-temperature monoclinic phase to a high-temperature trigonal structure, resulting in significant changes in both the emission spectrum shape of Eu ions and the depopulation kinetics of the 5D0 level. Consequently, X can be utilized as both a ratiometric and a lifetime-based luminescence thermometer, achieving maximal relative sensitivities of 3.4 and 1.0 or the respective approaches. Additionally, this work highlights how increasing the concentration of Eu3+ ions enables the tuning of the thermal operating range to achieve optimal thermometric performance. Moreover, an implementation of ratiometric approach of temperature sensing and imaging with X using digital camera without filters was demonstrated. This is the first report that demonstrates thermal imaging using Eu3+-solely doped phosphor. This finding underscores the potential of X as a versatile host material for advanced luminescent thermometry applications.

cond-mat.mtrl-sci↗

arXiv2025

NIR-to-NIR ratiometric and lifetime based luminescence thermometer on a structural phase transition in Na3Sc2(PO4)3:Yb3+

The ratiometric approach is the most commonly employed readout technique in luminescence thermometry. To address the trade-off between the risk of measurement disturbance in thermometers with high spectral separation of emission bands (due to dispersion in the surrounding medium) and the low sensitivity observed in ratiometric thermometers based on Stark level thermalization, we propose a thermometer based on the structural phase transition in . The use of Yb3+ ions as dopants and the changes in Stark level energies associated with the thermally induced monoclinic-to-trigonal phase transition enable the development of a thermometer with high relative sensitivity, achieving at 340K for N. Additionally, as demonstrated, the structural transition alters the probability of radiative depopulation of the 2F5/2 state of Yb3+, allowing the development of a lifetime-based luminescence thermometer. Furthermore, the phase transition temperature and consequently the thermometric performance of can be modulated by varying the Yb3+ ion concentration, offering additional tunability for specific applications.

cond-mat.mtrl-sci↗

arXiv2021

Phase transition facilitated highly sensitive luminescence nanothermometry and thermal imaging

Currently available temperature measurements or imaging at nano-micro scale are limited to fluorescent molecules and luminescent nanocrystals, whose spectral properties respond to temperature variation. The principle of operation of these conventional temperature probes is typically related to temperature induced multiphonon quenching or temperature dependent energy transfers, therefore, above 12%/K sensitivity and high thermal resolution remain a serious challenge. Here we demonstrate a novel class of highly sensitive thermographic phosphors operating in room temperature range with milikelvin thermal resolution, whose temperature readings are reproducible, luminescence is photostable and brightness is not compromised by thermal quenching. Corroborated with phase transition structural characterization and high spatio-temporal temperature imaging, we demonstrated that optically active europium ions are highly and smoothly susceptible to monoclinic to tetragonal phase transition in LiYO2 host, which is evidenced by changed number and the splitting of Stark components as well as by smooth variation of contribution between magnetic and electric dipole transitions. Further, reducing the size of phosphor from bulk to nanocrystalline matrix, shifted the phase transition temperature from 100oC down to room temperature. These findings provide insights into the mechanism underlaying phase transition based luminescence nanothermometry and motivate future research toward new, highly sensitive, high temporal and spatial resolution nano-thermometers aiming at precise studying heat generation or diffusion in numerous biological and technology applications.

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