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Hybrid nanogenerators are advanced mechanical energy harvesters capable of simultaneously scavenging multiple types of energy. Additionally, thermochromic materials provide a practical and visually assessable method for real‐time temperature monitoring. In this report, a novel energy harvester and sensing patch (EHSP) is introduced, that utilizes combined piezoelectric and triboelectric effects to harvest mechanical energy efficiently. To optimize the EHSP, various energy harvester configurations are fabricated and tested, and the dielectric properties of triboelectric films are systematically investigated. These improvements are implemented to augment the overall energy harvesting capability. The thermochromic properties of the EHSP are also explored to enhance both the electrical performance and thermal responsiveness. The EHSP demonstrates the ability to generate maximum voltage and current outputs of 350 V and 20.4 µA, respectively. Moreover, it can detect temperature changes within seconds, making it suitable for both energy harvesting and sensing applications. The EHSP is tested in practical scenarios, proving its efficiency as an energy harvester and sensor for everyday human activities. Furthermore, its integration with multiple hybrid nanogenerators showcases its potential for industrial and wearable sensing applications. [ABSTRACT FROM AUTHOR]

High‐sensitivity flexible wireless passive sensors with multiple parameters sensing capability are highly demanded for industrial production, structural health monitoring, and medical care. In this study, a microstructure‐enhanced temperature and pressure dual‐mode inductance capacitance (LC) sensor is developed with a particle swarm optimization‐back propagation (PSO‐BP) algorithm for simultaneous measurement of temperature and pressure. In the device, two interdigital electrodes connected at different parts of an inductor is used to realize dual‐mode measurement of pressure and temperature, with reduced volume and cost of the device as well as avoided interaction of the superimposed inductance. The sandpaper‐molded polydimethylsiloxane microstructures are employed to enhance the device sensitivity, with six and three times of improvement in temperature and pressure sensitivity, respectively. A PSO‐BP neural network suitable for regression analysis of low dimensional small sample data is constructed to achieve the simultaneous measurement of pressure and temperature with an accuracy up to 94%. Furthermore, investigations have proved the promising applications of the dual‐mode LC sensor in health monitoring of lithium‐ion batteries and detection of plantar pressure for medical care. [ABSTRACT FROM AUTHOR]

Crystalline α‐Gd2(MoO4)3 is synthesized by sintering at 800 °C using a coprecipitation method to prepare the precursor. The resulting α‐Gd2(MoO4)3 displayed a monocrystalline structure with a strong main peak (‐221) in the X‐ray diffraction signal. To develop a light‐emitting material, rare earth ions are added during synthesis. By doping with Tb3+ and Eu3+, the Gd2(MoO4)3 down‐conversion phosphor shows potential for use in UV–LED chips, counterfeit money prevention, and fingerprint identification. Additionally, co‐doping with [Er3+]/[Yb3+] and [Ho3+]/[Yb3+] ions produce green and red emissions when applied to a 980 nm LED chip, useful for anti‐counterfeit ink. The magnetic properties of gadolinium are leveraged to confirm magnetic resonance imaging luminescence. A flexible composite for heat detection and explored various applications for its use is also developed. [ABSTRACT FROM AUTHOR]

Eu2+‐doped phosphors have attracted the great attention of researchers in the past decade. However, Eu2+ dopant in inorganic hosts often suffers from the self‐oxidation effect, therefore causing the attenuated emission intensity and quantum efficiency. In this regard, developing Eu2+ doped phosphors with the prohibited self‐oxidation effect of Eu2+ and increased thermal stability is urgently required. Herein, an innovative cyan‐light emitting Li2CaSiO4:Eu2+/Eu3+, Lu3+ (LCSO) phosphor is designed. Both experimental results and theoretical calculations demonstrate that adding Lu3+ restricts the self‐oxidation of Eu2+ into Eu3+, thus improving the emission of Eu2+. Meanwhile, the Lu3+ introduction brings out excellent thermal stability. Finally, an efficient WLED with a color temperature (CCT) of 4573 K and a high color rendering index (Ra) of 84.2 is obtained using the as‐prepared phosphor due to the perfect compensation of the cyan light. As the introduction of Lu3+ improves the stability of Eu2+, a much greater difference in PL decay rate between Eu2+ and Eu3+ in LCSO is reached, thereby improving their sensitivity in temperature sensing. The strategy of Lu3+ introduction for prohibiting the self‐oxidation of Eu2+ for efficient and stable Eu2+ emission may stimulate some new ideas in designing high‐performance phosphors for more diverse applications. [ABSTRACT FROM AUTHOR]

The ever‐increasing demand for efficient and economic photonic materials has hastened the quest for robust, multifunctional phosphors. Herein, a dual‐mode luminescent SrLaLiTeO6:Er3+, Yb3+ double perovskite phosphor whose concentration‐dependent up and down‐conversion luminescence are investigated and underlying mechanisms are discussed. Temperature‐dependent up‐conversion luminescence of 2H11/2→4I15/2 transition exhibits negative thermal quenching, owing to the thermalization process from the 4S3/2 level. Temperature dependent Raman analysis confirms a decrease in the phonon lifetime from 0.43 to 0.28 ps indicating an increased number of phonon decay channels, which explains the rapid thermal quenching of up‐conversion emission at elevated temperatures. The diverse thermal quenching of the thermally coupled levels contributes to the exceptionally high relative sensitivity of 4.49 %K−1 at 140 K. A maximum sensitivity, Sr of 0.84 %K−1 (698 K) is obtained from the Raman‐PL intensity ratio (RPIR) of the ν1${\nu _1}$ band (719 cm−1) and the 986 nm emission band (4I11/2→4I15/2) of Er3+. Hence, by employing multi‐mode temperature sensing techniques a single phosphor can be used for optical thermometry for a broad temperature range from 90 to 698 K. In addition, the Near Infra‐Red (NIR)‐II emission of Er3+ corresponding to 4I13/2→4I15/2 transition shows excellent thermal stability, maintaining 72% of the room temperature intensity at 500 K. [ABSTRACT FROM AUTHOR]

High‐performance sensors with outstanding sensitivity, wide working range, and multifunctional properties are highly desirable in modern integrated smart wearable electronics. Herein, polydimethylsiloxane (PDMS)‐based stretchable pyroresistive sensors composed of tightly‐assembled silver nanowires (Ag NWs)‐encapsulated PDMS microspheres (PM) and expandable microspheres (EM) are fabricated. The synergistic cage‐like conductive network and EM endow the temperature sensor with tunable sensitivity (Max TCR: 27.4% °C−1), broad sensing range (25–85 °C), low perception limit (0.1 °C), and excellent anti‐interference ability. Interestingly, at elevated temperature field (> 90 °C), a remarkable conduction‐insulation transition is observed, which is employed to facilitate an early fire alarm system. In addition, the selectively distributed Ag NWs constructs segregated conductive pathways at an ultralow content (Pc = 0.014 vol%), leading to efficient electromagnetic interference shielding (40.0 dB). The underlying mechanism responsible for the observed superior thermosensation and EMI shielding performance is elucidated, and possible applications are demonstrated. Consequently, this work offers a novel strategy for the design of flexible, multifunctional pyroresistive sensors toward artificial intelligence and emerging wearable electronics. [ABSTRACT FROM AUTHOR]

Multimode luminescence is usually stimulated by various external stimuli in response to photon emission and is applied in various anti‐counterfeiting and encryption fields. However, integrating multimode luminescence into a single stable material, and how to quantitatively evaluate the relationship between temperature light and force light remains a challenge. In this work, LiNbO3:Er3+/Pr3+ microcrystals that can respond to X‐ray, UV light, temperature, and stress stimuli are developed. The temperature‐dependent upconversion emission spectra show a maximum relative sensitivity of 0.889% K−1 based on the intensity ratio. Meanwhile, the mechanoluminescence around 618 nm with a linear relationship is observed with the increase of force. These materials illustrate strong static and dynamic luminescence that can be manipulated in space and time dimensions, which provides new ideas in the field of anti‐counterfeiting and information encryption. [ABSTRACT FROM AUTHOR]

The realization of dual‐wavelength Mn2+ upconversion (UC) luminescence that exhibits different thermal responsive behaviors is promising for non‐invasive optical temperature sensing applications. However, it remains challenging to achieve such luminescence of Mn2+ ions. Herein, due to the site preference characteristics of Mn2+, color tunable and dual‐wavelength Mn2+ UC luminescence is achieved in K2NaScF6:Yb3+, Mn2+ by simply adjusting the Mn2+ doping concentration. Structural and spectral analysis as well as theoretical calculations reveal that the green and red UC emissions originate from two kinds of face‐sharing Yb3+‐Mn2+ dimers, which exhibit different luminescence properties, including different emission wavelength, excited state lifetime, full width at half maximum (FWHM), and luminescence thermal stability. This unique dual‐wavelength UC luminescence of Mn2+ provides a new type of fluorescence intensity ratio thermometer with absolute and relative sensitivities of up to 0.018 K−1 and 0.525% K−1, respectively. This work not only demonstrates the potential application of K2NaScF6:Yb3+, Mn2+ material in the field of optical thermometry but also provides new perspectives for designing multi‐band Mn2+ UC luminescence. [ABSTRACT FROM AUTHOR]

The article discusses the phosphorylation of phyB by GSK3s as a key mechanism that brings temperature sensors together in plants. It highlights the intricate crosstalk between light and temperature signals, which influence plant architecture, growth rate, and developmental transitions. The authors demonstrate that BIN2 phosphorylates phyB, contributing to photobody formation and stabilization, revealing a new mechanism in the regulation of phyB photobodies and temperature sensing. The research sheds light on the complex signaling networks plants use to optimize their developmental programs under different temperature regimes. [Extracted from the article]

Y2O3 codopedwith different Zr4+ (10% mol, 30%mol, and 49%mol) and constant Er3+ (2% mol) ions were successfully prepared via the laser annealing method. According to the XRD data, the lattice parameters decrease with the increase of Zr4+, and the grain size increases with Zr4+. The crystal space group switches from Ia-3 to Fm-3 m at a Zr4+ concentration of 49% mol. As the concentration of doped Zr4+ increases, the upconversion emission of Er3+ decreases. The nonequivalent substitution of Y3+ by Zr4+ creates lattice defects, which affect the fluorescence intensity of Er3+ ions in the material. The temperature sensing behavior of Y88%Zr10%Er2%O1.55 crystals based on the fluorescence intensity ratio between 4S3/2→4I15/2 and 4I9/2→4I15/2 transitions of Er3+ is studied. The results show that after codoping with Zr4+, the 4S3/2→4I15/2 and 4I9/2→4I15/2 transitions satisfy the Boltzmann distribution formula at temperatures above 333K. And the temperature sensing relative sensitivity can reach 2.96% K-1. [ABSTRACT FROM AUTHOR]

Respiration is one of the most important physiological processes of the human body. Continuous monitoring of respiration with wearable sensors can provide abundant information related to the health status of the respiratory system. However, the vast majority of the developed respiration sensors are constructed on nontextile substrates, resulting in dissatisfactory convenience, comfortness, and aesthetics. Additionally, special micro‐/nanomaterials are inevitably involved to construct the respiration sensors, which pose potential hazards to the human body due to the exfoliation and inhalation of these micro‐/nanomaterials. Here, humidity‐ and temperature‐sensitive electronic textiles (e‐Textiles) are presented, which are fabricated based on easily accessible and biofriendly materials (e.g., sodium chloride, glycerin, aluminum fiber, carbon fiber, and polyvinyl alcohol). Moreover, the proposed e‐Textiles use a potentiometric sensing mechanism, featuring self‐powered signal outputs and ultralow power consumption. The humidity and temperature‐sensing functionalities can also be in situ integrated into commercial masks for constructing full‐textile and all‐in‐one e‐Masks for comprehensive respiration monitoring. As demonstrations, both single‐point respiration monitoring (e.g., intensity, frequency, etc.) and 2D respiratory analysis (i.e., airflow distribution) can be realized with the e‐Masks. This work provides a facile and scalable approach to manufacture self‐powered and fully fabric respiration sensors for comprehensive respiratory analysis. [ABSTRACT FROM AUTHOR]

Hydrogen‐bonded organic frameworks (HOFs) have shown promise in various fields; however, the construction of HOF/polymer hybrid membranes that can maintain both structural and functional integrity remains challenging. In this study, we here fabricated a new HOF (HOF‐50) with reserved polymerizable allyl group via charge‐assisted H‐bonds between the carboxylate anion and amidinium, and subsequently copolymerized the HOF with monomers to construct a covalently bonded HOF/polymer hybrid (polyHOF) membrane. The resulting polyHOF membrane not only exhibits customizable mechanical properties and extreme stability, but also shows an exceptional ratiometric luminescent temperature‐sensing function with very high sensitivity and visibility even when the lanthanide content is two orders of magnitude lower than that of the reported mixed‐lanthanide metal–organic frameworks (MOFs) and lanthanide‐doped covalent organic frameworks (COFs). This orthogonal postsynthesis copolymerization strategy may provide a general approach for preparing covalently connected HOF/polymer hybrid membranes for diverse applications. [ABSTRACT FROM AUTHOR]

Medical surgical catheters are widely used in the medical field for drug delivery or postoperative drainage. However, infections associated with local temperature rise often occur at the catheter‐tissue interface, resulting in irreversible pathological damage, cognitive behavioral abnormalities, or even an increased risk of mortality if not monitored in time. Herein, an in situ temperature‐sensing hydrogel coating on the outer surface of medical surgical catheters for real‐time infection monitoring is developed. The hydrogel coating exhibits a record temperature coefficient of resistance of 2.90% °C−1 and maintains stable in vivo. Besides, the hydrogel layer forms a mechanically compatible catheter‐tissue interface and minimizes the risk of inflammatory responses due to its tissue‐like softness (Young's modulus of 4.24 kPa). By applying it in the early detection of infections in the brain of SD rats, the individual survival rate has increased to 90% with timely intervention. [ABSTRACT FROM AUTHOR]

Near‐infrared (NIR) II region (1000–1700 nm) lighting sources possess special potential for temperature sensing and quantitative composition analysis. However, it is a challenge to tune the luminescence toward such long wavelength NIR‐II emission. Herein, Cr4+ ions occupation is designed and verified in olivine‐type CaYGaO4 as [CrO4] tetrahedron by site occupancy confinement. Under 620 nm red light excitation, the phosphors display broadband NIR‐II emission centered at 1330 nm with a full width at half maximum (FWHM) of 233 nm, resulting from spin‐allowed 3T2 to 3A2 transition of Cr4+ ions in Td symmetry. The optical thermometry application is demonstrated by decoding the spectral shift and decay times varying with temperature, and the maximum relative sensitivities are 5.82% and 0.78% K−1, respectively. Furthermore, a flexible film containing CaYGaO4:Cr4+ is fabricated to implement the non‐invasive detections of fillet temperature and NH3 concentration in ammonia. This work represents a step toward developing next‐generation NIR‐II luminescence materials and widens non‐invasive detection applications. [ABSTRACT FROM AUTHOR]

Converting mechanical energy into photon emission provides a promising route for intelligent sensing, self‐powered lighting, and distributed energy harvesting, which is of great significance for finding a feasible solution to the current sensing technical bottleneck and energy crisis. As the basis for understanding the conversion mechanism and realizing high‐frequency mechanical energy utilization, elucidating the dynamic process of intensity variation in the mechano‐to‐photon conversion remains a great challenge. Herein, a time‐domain characterization scheme that enables to unravel the intrinsic decay of mechanoluminescence (ML) with lifetimes from milliseconds down to tens of microseconds is constructed. It is demonstrated that ML decay characterization is an important tool to reveal the dynamics of charge migration in ML materials. The ML decay in a typical self‐reproducible ML material ZnS:Mn2+ shows temperature dependence and stress fluctuation resistance, which opens up a new reliable approach for self‐powered and remote temperature sensing. Finally, benefiting from the shortest ML lifetime recorded to date, an ultrafast‐response stress sensor that enables to detect individual pulses of ultrasonic waves with ML sensing technology is developed. [ABSTRACT FROM AUTHOR]

Corannulene‐derived materials have been extensively explored in energy storage and solar cells, however, are rarely documented as emitters in light‐emitting sensors and organic light‐emitting diodes (OLEDs), due to low exciton utilization. Here, we report a family of multi‐donor and acceptor (multi‐D‐A) motifs, TCzPhCor, TDMACPhCor, and TPXZPhCor, using corannulene as the acceptor and carbazole (Cz), 9,10‐dihydro‐9,10‐dimethylacridine (DMAC), and phenoxazine (PXZ) as the donor, respectively. By decorating corannulene with different donors, multiple phosphorescence is realized. Theoretical and photophysical investigations reveal that TCzPhCor shows room‐temperature phosphorescence (RTP) from the lowest‐lying T1; however, for TDMACPhCor, dual RTP originating from a higher‐lying T1 (T1H) and a lower‐lying T1 (T1L) can be observed, while for TPXZPhCor, T1H‐dominated RTP occurs resulting from a stabilized high‐energy T1 geometry. Benefiting from the high‐temperature sensitivity of TPXZPhCor, high color‐resolution temperature sensing is achieved. Besides, due to degenerate S1 and T1H states of TPXZPhCor, the first corannulene‐based solution‐processed afterglow OLEDs is investigated. The afterglow OLED with TPXZPhCor shows a maximum external quantum efficiency (EQEmax) and a luminance (Lmax) of 3.3 % and 5167 cd m−2, respectively, which is one of the most efficient afterglow RTP OLEDs reported to date. [ABSTRACT FROM AUTHOR]

Some organic dyes and photosensitizers with strong visible absorption can behave as photo‐responsive oxidase mimics. However, the relationship between the photo‐oxidase activity and molecular structure remains unclear to date. In this work, a new type of photosensitizer with the characteristics of molecular rotors, namely DPPy, served as the molecular scaffold for further investigation. To adjust the photocatalytic oxidation ability, DAPy and CBPy were designed and synthesized based on the enhancement and diminishment of the intramolecular charge transfer (ICT) process, respectively. Kinetic studies revealed that DAPy and CBPy both exhibited highly efficient photo‐activated oxidase‐like activity with 3,3′,5,5′‐tetramethylbenzidine (TMB) as the substrate, which were in good accordance with their molecular engineering to promote either type I or type II reactive oxygen species (ROS) generation. Impressively a colorimetric method based on the visible light induced oxidase‐like activity of molecular rotors was developed to determine the environmental temperature for the first time. Both DAPy and CBPy showed distinct sensitivities toward temperature as compared with several molecular rotors based on the typical fluorimetric detection. This work provides a new strategy for the application of molecular rotors to overcome the non‐emissive challenge in temperature sensing. [ABSTRACT FROM AUTHOR]

Cr3+‐activated near‐infrared (NIR) phosphors are one of the most influential candidates for the new generation of intelligent NIR phosphor‐converted light‐emitting diode (pc‐LED) light sources. For spectral analysis, the broader the spectrum, the more useful information it contains. Herein, ultra‐broadband Cr‐activated Sc2O3 nanophosphors, which exhibit NIR ultra‐broadband from 650 to 1600 nm, are developed by the sol–gel method. This ultra‐broadband emission originates from the presence of Cr3+ and Cr4+, two luminescent centers confirmed by diffuse reflection spectra, electron paramagnetic resonance, time‐resolved photoluminescence spectra, and temperature‐dependent emission spectra. The nanophosphor exhibits excellent temperature‐sensing performance with SA = 4.102% K−1 and SR = 1.855% K−1. Co‐doping Yb3+ into Sc2O3 nanophosphors builds the Cr3+‐Yb3+‐Cr4+ model to bridge the spectral gap located at 1000 nm, forming a continuous NIR ultra‐broadband spectrum ranging from 650 to 1600 nm for the first time. Moreover, the introduction of Yb3+ improves the thermal stability of nanophosphors from 29.49% to 50.65% at 150 °C. The NIR transmission spectra of water, ethanol, and peanut oil demonstrate that Sc2O3:Cr3+‐Yb3+‐Cr4+ NIR nanophosphors favor potential applications in spectral analysis. The construction of a Cr3+‐Yb3+‐Cr4+ spectral bridge for realizing NIR ultra‐broadband phosphors based on cheap blue LEDs provides novel and effective insights. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Hyperbranched polysiloxanes have attracted increasing interest due to their unique fluorescence properties. However, the relatively short emission wavelength and low fluorescence lifetime are still the main obstacles to their broader application. In this study, we first synthesized a β‐diketone contained hyperbranched polysiloxane with excitation‐dependent multicolor emission. Further through the coordination of HBPSi‐NMDEA with Eu3+ ion, a hybrid luminescent material was prepared. It exhibited not only aggregation‐induced red emission at 613 nm, but also a long fluorescence lifetime of 681.45 μs. Particularly, it showed highly sensitive reversible fluorescence response to temperature variation, thus displaying the potential to be used in fluorescence temperature detection. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Hyperbranched polysiloxanes have attracted increasing interest due to their unique fluorescence properties. However, the relatively short emission wavelength and low fluorescence lifetime are still the main obstacles to their broader application. In this study, we first synthesized a β‐diketone contained hyperbranched polysiloxane with excitation‐dependent multicolor emission. Further through the coordination of HBPSi‐NMDEA with Eu3+ ion, a hybrid luminescent material was prepared. It exhibited not only aggregation‐induced red emission at 613 nm, but also a long fluorescence lifetime of 681.45 μs. Particularly, it showed highly sensitive reversible fluorescence response to temperature variation, thus displaying the potential to be used in fluorescence temperature detection. [ABSTRACT FROM AUTHOR]

Recently high doping of lanthanide ions (till 100 %) is realized unprecedentedly in nanostructured upconversion (UC) phosphors. However, oddly enough, this significant breakthrough did not result in a corresponding UC enhancement at ambient temperature, which hinders the otherwise very interesting applications of these materials in various fields. In this work, taking the Er3+‐rich UC nanosystem as an example, we confirm unambiguously that the phonon‐assisted cross relaxation (CR) is the culprit. More importantly, combining the theoretical modeling and experiments, the precise roles of different CR channels on UC energy loss are quantitatively revealed. As a result, lowering the temperature can exponentially enhance the relevant UC luminescence by more than two orders of magnitude. Our comprehension will play an important role in promoting the UC performance and further application of high doping rare earth materials. As a proof of concept, an Er3+‐rich core/multi‐shell nanophosphor is exploited which demonstrates the great potential of our finding in the field of ultra‐sensitive temperature sensing. [ABSTRACT FROM AUTHOR]

Simultaneous photothermal ablation of multiple tumors is limited by unpredictable photo‐induced apoptosis, caused by individual intratumoral differences. Here, a multi‐channel lanthanide nanocomposite was used to achieve tailored synergistic treatment of multiple subcutaneous orthotopic tumors under non‐uniform whole‐body infrared irradiation prescription. The nanocomposite reduces intratumoral glutathione by simultaneously activating the fluorescence and photothermal channels. The fluorescence provides individual information on different tumors, allowing customized prescriptions to be made. This enables optimal induction of hyperthermia and dosage of chemo drugs, to ensure treatment efficacy, while avoiding overtherapy. With an accessional therapeutic laser system, customized synergistic treatment of subcutaneous orthotopic cancer cases with multiple tumors is possible with both high efficacy and minimized side effects. [ABSTRACT FROM AUTHOR]

A multifunctional double‐perovskite‐type Ca2LnSbO6 (Ln = La, Y, Gd, and Lu) phosphors with Eu3+ and Mn4+ co‐doped were successfully synthesized and designed to simultaneously apply to temperature sensing and plant growth LED. With temperature varying from 303 to 523 K, the integrated intensity of Mn4+ ions (2Eg → 4A2g) markedly decline swifter comparing to Eu3+ ions (5D0 → 7F2) due to the thermal quenching effect. It implies that Mn4+ is susceptive to the temperature in this work. Eu3+ exhibits high heat resistance, which can be selected as a calibration parameter for the fluorescence intensity ratio temperature sensor. The maximum relative sensitivity (Sr) values of Ca2LnSbO6:1%Eu3+, 0.5%Mn4+ (Ln = La, Y, and Gd) phosphor are estimated as 2.19% K−1 at 443 K, 1.68% K−1 at 503 K, and 1.80% K−1 at 483 K, respectively. They are superior to many recent emerging phosphors. Moreover, upon 365 nm excitation, Ca2LnSbO6:1%Eu, 0.5%Mn (Ln = La, Y, Gd, and Lu) phosphors display a wide red emission peaking at 696, 680, 677, and 684 nm, respectively. They come from the overlapped of 2Eg–4A2g of Mn4+ and 5D0–7F4 transition of Eu3+. Their full widths at half maximum are 34, 35, 35, and 29 nm, respectively. They are all perfectly overlapping the absorption curves of chlorophyll a and chlorophyll b, and their fabricated red phosphor‐converted light‐emitting diode device ulteriorly corroborated the promising applications for plant growth. Markedly, the systematic analysis of their crystal chemistry and site preferentially occupancy is first reported and discussed by the bond valence theory. [ABSTRACT FROM AUTHOR]

In this work, a method for controllable regulation of crystal form was proposed for the first time and the effects of different crystal forms on the up‐conversion luminescence properties of Ho3+, Yb3+ co‐doped K3Sc0.5Lu0.5F6 (KSLF) phosphors was explored. KSLF:Ho3+, Yb3+ phosphors were synthesized by the high temperature solid‐state reaction method, and X‐ray diffraction (XRD) results illustrate that the compounds can obtain monoclinic phase and cubic phase at different synthesis temperatures. In addition, according to the power‐dependent up‐conversion luminescence (UCL) intensity, the UCL mechanism and the electronic transition process are discussed. Simultaneously, the temperature sensing behavior of the best samples with different crystal forms at different temperatures was studied by fluorescence intensity ratio technique. All the results show that KSLF:Ho3+, Yb3+ phosphors show great application potential in the field of temperature sensing, and the preparation of KSLF:Ho3+, Yb3+ in different crystal forms can provide a reference value for crystal design and growth. [ABSTRACT FROM AUTHOR]

Lanthanide‐doped halide perovskite has emerged as a promising phosphor for multimode luminescence. Here, a chloride‐based perovskite single crystal is reported, namely Cs2NaInCl6:Yb3+,Er3+, that is grown in a hydrothermal reactor. The as‐grown crystals feature two distinct luminescence behaviors under UV and 980 nm laser excitation, respectively. Under UV lamp excitation, the crystal shows a multicolor emission of sharp bands at 448, 550, and 660 nm, covering a wide color gamut in CIE diagram. In stark contrast, the crystal under 980 nm excitation exhibits a pure green upconversion with a green‐to‐red ratio up to 211. The universal green dominance is further demonstrated in many chlorides, including Cs2AgInCl6, Cs2NaBiCl6, and Cs2AgBiCl6. The strong green upconversion is used for optical thermometry, which demonstrates an unprecedented sensitivity up to 9.3% K−1 at the low temperature end. The work introduces a kind of new hosts for single‐band upconversion luminescence, opening up many possibilities in areas such as low‐threshold laser and pure‐green color converter. [ABSTRACT FROM AUTHOR]

A simple temperature sensor based on ZnO composite graphene is demonstrated. With the temperature changes, the electron mobility of ZnO composite graphene changes accordingly, which leads to an effective change in the refractive index of ZnO composite graphene. Experimental results show that micro‐nano fiber coated with spherical ZnO composite graphene exhibits a higher sensitivity of 0.018 dB/°C in the temperature range of 25–60°C. Overall, the results verify the effectiveness of the proposed temperature sensor in accurate temperature measurement and offer a new, unique, and convenient direction for temperature sensing. [ABSTRACT FROM AUTHOR]

For biological embryo incubation, it is very important to monitor temperature accurately, so a new Mach–Zder interference (MZI) fiber temperature sensor is based on a microfiber coupler (MFC). It consists of a 3 dB fiber coupler and MFC forming an MZI structure. Since the MFC has strong evanescent field properties, higher sensitivity can be generated when fully acting with the external temperature environment. The experimental results show that the optical fiber sensor has good temperature response properties in the temperature range of 24–38°C, and the temperature sensitivity increases rapidly as the MFC waist diameter decreases. The maximum wavelength sensitivity of approximately 191.93 pm/°C and R2 = 0.98739, with the advantages of high sensitivity, simple manufacturing, and low cost can be applied in the field of bioincubation temperature monitoring. [ABSTRACT FROM AUTHOR]

The efficient upconversion (UC) particles based on fluorescence intensity ratio (FIR) technique are developed for application in novel temperature sensors. Herein, Yb3+/Er3+‐codoped Gd2(WO4)3 particles are prepared by coprecipitation method and subsequent calcination. The phase structure and surface morphology of the particles are systematically analyzed. The UC emission spectrum of Gd2(WO4)3:Yb3+/Er3+ particles are mainly composed of two strong emission bands centered at 530 and 551 nm, respectively. Moreover, the optimum doping concentration of Yb3+ and Er3+ is fixed at 10% and 2%, respectively. UC emission mechanism based on two‐photon process is investigated by studying the pump power excitation dependence and fluorescence decay behavior of Gd2(WO4)3:10%Yb3+/2%Er3+ particles. The excellent temperature sensing capability of Gd2(WO4)3:10%Yb3+/2%Er3+ particles is implemented from thermally coupled levels (TCLs) of Er3+. Notably, the maximum absolute sensitivity (Sa) and relative sensitivity (Sr) based on TCLs by 2H11/2/4S3/2 levels are 1.39 %K−1 (at 518 K) and 1.18 %K−1 (at 293 K), respectively. As a result, Gd2(WO4)3:10%Yb3+/2%Er3+ particles have a great potential for application in noncontact temperature sensors. [ABSTRACT FROM AUTHOR]

The efficient upconversion (UC) particles based on fluorescence intensity ratio (FIR) technique are developed for application in novel temperature sensors. Herein, Yb3+/Er3+‐codoped Gd2(WO4)3 particles are prepared by coprecipitation method and subsequent calcination. The phase structure and surface morphology of the particles are systematically analyzed. The UC emission spectrum of Gd2(WO4)3:Yb3+/Er3+ particles are mainly composed of two strong emission bands centered at 530 and 551 nm, respectively. Moreover, the optimum doping concentration of Yb3+ and Er3+ is fixed at 10% and 2%, respectively. UC emission mechanism based on two‐photon process is investigated by studying the pump power excitation dependence and fluorescence decay behavior of Gd2(WO4)3:10%Yb3+/2%Er3+ particles. The excellent temperature sensing capability of Gd2(WO4)3:10%Yb3+/2%Er3+ particles is implemented from thermally coupled levels (TCLs) of Er3+. Notably, the maximum absolute sensitivity (Sa) and relative sensitivity (Sr) based on TCLs by 2H11/2/4S3/2 levels are 1.39 %K−1 (at 518 K) and 1.18 %K−1 (at 293 K), respectively. As a result, Gd2(WO4)3:10%Yb3+/2%Er3+ particles have a great potential for application in noncontact temperature sensors. [ABSTRACT FROM AUTHOR]

The neutral nitrogen‐vacancy (NV0) defects in diamond are photostable color centers, suitable for a wide range of applications in science and engineering. However, the photophysical properties of the centers have not yet been fully characterized. This work measured the stimulated emission cross sections of NV0 in a single‐crystal diamond by two‐photon excitation of its matrix at 344 nm. From the measured photoluminescence spectrum and the fluorescence lifetime of 20 ± 1 ns, we determined a peak stimulated emission cross section of 1.43 ± 0.07 × 10−17 cm2 at 650 nm for the NV0 centers. In addition, we have also examined the thermal shifts of the zero‐phonon line of NV0 centers in nanoscale diamonds (~100 nm in diameter) over the temperature range of 30–120°C. A temperature measurement sensitivity of 0.2 K·Hz−1/2 was achieved, which is about two‐fold better than that of NV−, despite that the fluorescence intensity of NV0 is about six‐fold lower than that of NV− in the same nanoparticles. The result is attributed to the smaller electron–phonon coupling strength of the neutral center, compared with its negatively charged counterpart. [ABSTRACT FROM AUTHOR]

Multiparameter sensors that can individually monitor mechanical and thermal signals from multiple stimuli have attracted immense attention. Due to interferences caused by signal crosstalk, it is a challenge for multiparameter sensors to simultaneously differentiate mechanic and thermal stimuli within a broad working range. Herein, a liquid‐metal‐based stretchable dual‐parameter sensor that can simultaneously detect deformation (0–4.5 mm) and temperature (0–60 °C) is fabricated. The sensor adopts a multilayer structure in which a capacitive deformation‐sensing unit is stacked on top of a resistive temperature‐sensing unit. The deformation unit possesses excellent linear responses (R2 = 0.999) and ultralow detection limit (0.04 mm, ≈0.02%). Attributed to these merits, the deformation unit can be used to monitor physiological actions (e.g., finger bending, swallowing, and speaking). The temperature unit exhibits strong stability under multiple stimuli. With the cooperation of the two units, the dual‐parameter sensor can accurately differentiate deformation and temperature stimuli with an average error of 0.04 mm and 0.82 °C. Because of these remarkable performances, the sensor can achieve real‐time acquisition of the deformation and temperature change during finger movements. The dual‐parameter sensing abilities of the sensor indicate its promising potential in human motion monitoring and wearable devices. [ABSTRACT FROM AUTHOR]

As alternatives to electronic devices, optically active structures from responsive nanomaterials offer great opportunity for building up smart functional sensors. This work reports on the construction and application of photonic microcapsules (PMCs) for colorimetric temperature microsensors, enabling miniaturization for injectable local micro‐area sensing and integration for large‐area sensing. Monodispersed PMCs are produced by in situ photopolymerization of hydrogel shells of cholesteric liquid crystal (CLC)‐in‐water‐in‐oil double emulsion droplets prepared using microfluidic devices, with controllable physical structures and chemical compositions. Constructed PMCs exhibit thermal responsive structural color according to the selective Bragg reflection of CLC's periodical helical structures within the microdroplet's spherical confinement. CLC mixtures with phase transition temperature of 56.0 and 37.8 °C have been prepared and employed to construct PMCs exhibiting obviously visible and quantifiable optical response in 52–56 and 33–38 °C, respectively. The PMCs have been successfully applied for monitoring the living cell extracellular temperature via co‐incubation with cell suspension, and for sensing human forehead temperature via a flexible device from assembled PMCs. These PMCs can be flexibly applied in either micro‐environment or large‐area surface, enabling wide applications for a precision temperature monitoring of biological activities (e.g., cells or organs), optoelectronic devices working conditions (e.g., temperature indicators under extreme conditions), etc. [ABSTRACT FROM AUTHOR]

Lanthanide metal–organic frameworks (Ln‐MOFs) are promising for luminescence detection of volatile organic compound (VOC) vapors, but usually suffer from the silent or quenched Ln3+ emission. Herein, we report a new dual‐emissive Eu‐MOF composed of the coordinatively unsaturated Eu9 clusters that afford abundant open metal sites to form a confined "binding pocket" to facilitate the preconcentration and recognition of VOCs. Single‐crystal structural analyses reveal that specific analytes can replace the OH oscillators in the first coordination sphere of Eu3+ and form a unique hydrogen‐bonding second‐sphere adduct tying adjacent Eu9 clusters together to minimize their nonradiative vibrational decay. With the promoted Eu3+ luminescence, the MOF realizes real‐time in situ visual sensing of THF vapor (<1 s) and shows a quantitative ratiometric response to the vapor pressure with a limit of detection down to 17.33 Pa. Also, it represents a top‐performing ratiometric luminescent thermometer. [ABSTRACT FROM AUTHOR]

Here, Bi3+, Er3+ co‐activated gadolinium phosphors with multimode emission properties are prepared, which can emits blue, green, and orange light under the excitation of ultraviolet, 980 and 1550 nm, respectively. Moreover, BaGd2O4:Bi3+, Er3+ can show multicolor luminescence under different excitation conditions, such as pump light source, ambient temperature, working current, and other factors. Based on the dynamic luminescence characteristics, the dynamic anti‐counterfeiting experiments are designed based on the phosphor. At the same time, the material also shows multimode temperature sensing characteristics. Under the excitation of 980 nm laser, three strong up‐conversion signals Er3+ ions are generated at 528 nm (2H11/2), 555 nm (4S3/2), and 668 nm (4F9/2), which have different temperature dependences. Based on the fluorescence intensity ratio between thermal‐coupled energy levels (2H11/2/4S3/2) and nonthermal‐coupled energy levels (2H11/2/4F9/2) of Er3+ ions, respectively, the dual‐mode temperature thermometer was constructed with high‐temperature sensitivity. In addition, the fluorescence lifetime of Bi3+ ions also has a strong temperature dependence, which can be used as another temperature detection signal, greatly improving the stability of thermometers under harsh conditions. Therefore, the material has a bright prospect in the field of anti‐counterfeiting and temperature sensing. [ABSTRACT FROM AUTHOR]

Ratiometric near‐infrared (NIR) fluorescence holds great promise for important applications such as temperature sensing, food safety detection, and biological imaging owing to its self‐calibration and contactless measurements in the NIR region. For ratiometric NIR fluorescence, the suppression of optical reabsorption and signal interference is crucial. In this work, freestanding erbium (Er)‐hyperdoped silicon quantum dots (Si QDs) with UV absorption and NIR emission are synthesized via nonthermal plasma, effectively avoiding optical reabsorption. Er with the valence of +3 is found to be mainly located in the subsurface region of Er‐hyperdoped Si QDs, which emit NIR light at the wavelengths of 830 and 1540 nm. The distinct difference between the two NIR wavelengths (Δλ = 710 nm) well impedes signal interference in ratiometric NIR fluorescence. It is shown that Er‐hyperdoped Si QDs may be a powerful platform of ratiometric NIR fluorescence by exemplarily demonstrating their temperature‐sensing capability in a wide temperature range (297–477 K) with high relative sensitivity (3.05% K−1), high‐temperature resolution (<0.018 K), and high repeatability (>98%). The temperature sensing of Er‐hyperdoped Si QDs may be further employed to construct logic gates, enabling in‐sensor computing. [ABSTRACT FROM AUTHOR]

An initial investigation on the employment of targeted structural alterations, achieved through the post‐synthesis modification method, for modulation of the thermometric properties of metal–organic frameworks (MOFs) is reported. The MOF Eu0.05Tb0.95‐NBDC (NBDC = 2‐amino‐1,4‐benzenedicarboxylate) is chosen as pristine material, and its terminal N,N‐dimethylformamide (DMF) molecules are exchanged by various terminal and chelating ligands through a single‐crystal‐to‐single‐crystal coordinating solvent exchange reaction. Temperature‐dependence luminescence studies reveal that all samples are highly sensitive in the medium range with a maximum relative sensitivity of 2.6% K−1 at 190 K for Eu0.05Tb0.95‐NBDC. In addition, a shift of 50 K of the operating temperature range is evidenced for the exchanged analogs. This is attributed to the occurrence of different deactivation pathways in the exchanged analogs due to the presence of N‐donor terminal or N/O‐donor chelating aromatic ancillary ligands in the place of DMF terminal ligands in the pristine material. Overall, this work provides insights into the role of terminal and chelating ligands on the thermometric properties of mixed Eu–Tb MOFs and proposes a promising strategy to control and modulate their thermometric performances. [ABSTRACT FROM AUTHOR]

A series of Na0.5Bi2.5Nb2−xTaxO9 (NBN2−xTx):Er3+/Yb3+ upconversion luminescence (UL) phosphors were prepared by a solid‐state sintering method, and the lattice structure of the prepared samples was studied by X‐ray diffraction. Under 980‐nm laser excitation, the UL properties were investigated by a spectrophotometer from room temperature to 723 K, and the optimal concentration of co‐doping Er3+/Yb3+ is 0.14 and 0.26 by replacing Bi3+ sites in NBN2−xTx host, respectively. With the increase of Ta5+ concentration, the color of UL gradually changes from green to yellow corresponding color coordinates from (0.301, 0.682) to (0.441, 0.549) under 980‐nm laser excitation. This color change is attributed to the decrease of lattice unit volume leading to the increase of cross relaxation of Er3+ to Er3+ and energy back transfer from Er3+ to Yb3+. Using the luminescence intensity ratio technique, the maximum absolute sensitivities (SA) are obtained as 0.00674 K−1 at 538 K and 0.00603 K−1 at 573 K, and relative sensitivities (SR) are obtained as 0.01174 K−1 at 303 K and 0.01244 K−1 at 303 K based on 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 energy level transitions of Er3+ in NBN2:0.14Er3+/0.26Yb3+ phosphors under 980‐ and 1550‐nm laser excitations, respectively. The results suggest that the NBN2−xTx:Er3+/Yb3+ phosphors are promising candidates for temperature sensing with different UL colors. [ABSTRACT FROM AUTHOR]

Plasmonic semiconductor nanoparticles (NPs) with wide‐range tailorable localized surface plasmon resonance (LSPR) hold exciting prospects on optical signal amplification. In this work, by precisely controlling oxygen vacancies around W atoms, plasmonic bismuth tungstate Bi2WO6 (BWO) nanosheets are constructed to enhance emission of Yb3+/Er3+ co‐doped NaYF4 upconversion nanoparticles (UCNPs). In the optimal conditions, the UCNPs/BWO‐2 hybrids exhibit over three‐order (1260‐fold) enhancement selectively on the 520 nm emission owing to the strong LSPR‐induced electrical field and photothermal effect. Moreover, it is found that the highly efficient emission of UCNPs/BWO‐2 allows it to act as a thermometer to monitor the real‐time local temperature with high absolute sensitivity of 5.8 × 10−3 K−1 in wide temperature range (up to 990 K). For proof‐of‐concept, the dual functions of plasmonic UCNPs/BWO‐2 hybrids on bioimaging and photothermal therapy for cancer cells are demonstrated that can be completely killed within 5 min under 980 nm irradiation. As far as it is known, this work reaches a new level on UCNPs emission enhancement by plasmonic semiconductor, exceeding most plasmonic metals. [ABSTRACT FROM AUTHOR]

Magnetic resonance imaging (MRI)‐tuned radio‐frequency (RF) sensors are used as a radiation‐free alternative for tracking minimally invasive medical tool positions. However, in situ temperature sensing capabilities of the MRI‐tuned RF sensors have not been thoroughly investigated yet. A self‐resonating RF sensor capable of remote in situ temperature sensing during real‐time interventional MRI is presented. The proposed RF sensor design relies on the temperature‐dependent permittivity to tune or detune the resonant frequency. The sensor is tuned to match the resonant frequency of a 7 Tesla MRI (298 MHz) at body temperature, enabling a hyperintense signal in MR images. As temperature increases, the sensor detunes due to the change in the relative permittivity, and the hyperintense signal disappears in the MR image, serving as a direct visual indicator of the temperature change in real‐time. In addition, the localized signal can be used for 3D position tracking of interventional medical devices. Using a 7 Tesla preclinical MRI, in vitro characterization and ex vivo feasibility of the proposed temperature sensing method are demonstrated in the clinically relevant temperature range of 36–42 °C with an accuracy of ±0.6 °C. Such RF sensors can provide safer operations in future MRI interventional procedures. [ABSTRACT FROM AUTHOR]

Green thermochromic materials are of great interest in many applications. Thermochromic and phase change materials are commonly used as smart devices to facilitate temperature sensing and passive heating/cooling systems, respectively. Since most of the current thermochromic materials are nondegradable, toxic, and/or nongreen, there is great opportunity to develop greener materials with high performance considering the wide range of materials that can exhibit thermochromism. This concise review distinguishes the different forms, phases, and chemical structures of thermochromic materials. A brief history of thermochromism is reviewed and a general distinction between reversible and irreversible thermochromism is provided. A general definition of green materials is provided, recent advances in the emerging field are critically discussed as well as future applications. This review also provides brief but thorough understanding of mechanistic pathways of this phenomenon in materials and the constituent requirements of green materials such that new systems can be designed using nontoxic, biobased, and/or biodegradable materials. Such green thermochromic materials will expand their use significantly. [ABSTRACT FROM AUTHOR]

The doping of transition metal ions in the up‐conversion (UC) luminescent material doped with Yb3+/Ln3+ is a facile way to increase their UC luminescence intensities and alter their colors. In this study, La2MgTiO6:Yb3+/Mn4+/Ln3+ (Ln3+ = Er3+, Ho3+, and Tm3+) phosphors showing excellent luminescence properties were prepared by a solid‐state method. The sensitivity of the La2MgTiO6:Yb3+/Ln3+/Mn4+ phosphor was double that without Mn4+, because Mn4+ affects the UC emissions of Ln3+ via energy transfer between these ions. Moreover, Mn4+ also acts as a down‐conversion activator, which can combine with UC ions to achieve multi‐mode luminescence at different wavelengths. Under 980 nm excitation, these samples emit green light (from Er3+ and Ho3+) and blue light (from Tm3+). In contrast, under 365 nm excitation, they emit red light (from Mn4+). Further testing revealed that the La2MgTiO6:Yb3+/Mn4+/Ln3+ phosphors have potential applications in temperature sensing and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Accurate and real‐time detection of human body temperature changes is crucial to understand thermal homeostasis, to access complex health conditions, and to further build a smart healthcare system. Recent years have seen temperature sensors open up many potential applications in electronic skin, artificial intelligence, and next‐generation smart robots. Currently, traditional mercury and infrared thermometers are extensively used for human body temperature detection. However, they still suffer from rigid appearance, slow response, insufficient sensitivity, low accuracy, and potential harm risk to the users. Therefore, it is highly desired to develop more breathable, deformable, and economically available functional materials to construct the flexible high performance temperature sensors. Alternatively, fiber materials have attracted more attention owing to their soft, flexible, deformable, and porous features. This review summarizes a comprehensive research advancement in the field of flexible temperature sensors constructed with fiber materials. Temperature sensing mechanisms, functional constructing materials, performance characterizations, practical applications, and fiber‐based temperature sensors with different structural designs are systematically introduced at great length. Research outlook and prospects will be presented to inspire the potential readers. [ABSTRACT FROM AUTHOR]

The doping of transition metal ions in the up‐conversion (UC) luminescent material doped with Yb3+/Ln3+ is a facile way to increase their UC luminescence intensities and alter their colors. In this study, La2MgTiO6:Yb3+/Mn4+/Ln3+ (Ln3+ = Er3+, Ho3+, and Tm3+) phosphors showing excellent luminescence properties were prepared by a solid‐state method. The sensitivity of the La2MgTiO6:Yb3+/Ln3+/Mn4+ phosphor was double that without Mn4+, because Mn4+ affects the UC emissions of Ln3+ via energy transfer between these ions. Moreover, Mn4+ also acts as a down‐conversion activator, which can combine with UC ions to achieve multi‐mode luminescence at different wavelengths. Under 980 nm excitation, these samples emit green light (from Er3+ and Ho3+) and blue light (from Tm3+). In contrast, under 365 nm excitation, they emit red light (from Mn4+). Further testing revealed that the La2MgTiO6:Yb3+/Mn4+/Ln3+ phosphors have potential applications in temperature sensing and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Eu2+‐, Mn2+‐ and Eu2+−Mn2+‐doped CaMgSi2O6 phosphors have been prepared by a high‐temperature solid‐state reaction. Systematic investigation of the concentration‐ and temperature‐dependent luminescence of Mn2+ showed that Mn2+ ions occupy two distinct sites in CaMgSi2O6. Electron–vibration interaction (EVI) analyses of Mn2+ ions revealed Huang–Rhys factors of 4.73 and 2.82 as well as effective phonon energies of 313 and 383 cm−1 for the two sites. Eu2+−Mn2+ energy transfer is also discussed, and its efficiency is estimated by lifetime and luminescence spectra. The different thermal quenching behaviours of Eu2+ and Mn2+, the distinct emission colours of Eu2+ (blue, band peak at ∼451 nm) and Mn2+ (yellow–red range, band peaks at ∼583 and 693 nm) endow the co‐doped samples with potential applications in luminescence thermometry and temperature‐/excitation wavelength‐responsive dual anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Physiological temperature is closely linked to biological processes and thus its precise sensing is essential. Lanthanide MOFs materials as fluorescence temperature sensors exhibits a plenty of advantages and have been explored as thermometers. However, the synthesis of Ln‐MOFs are usually under tough conditions and suffered from unsatisfactory water stabilities. In addition, most fluorescence thermometers are based on temperature‐dependent fluorescence intensity mechanism, which are heavily influenced by subtle changes and result in detection inaccuracy. Hence, we presented a dual‐emitting composite material MOF‐867@Eu3+@carbon dots as ratio fluorescence thermometers by simple post‐modification strategy. This prepared MOF‐867@Eu3+@CDs showed a highly splendid sensitivity in the range of 20–60 °C and showed low cell toxicity. It was expected that MOF‐867@Eu3+@CDs could be promising candidates in physiological temperature sensing application. [ABSTRACT FROM AUTHOR]

The hosts with low maximum phonon energy (MPE) are preferred since the nonradiative consumption of the luminescence centers in them are low. Among the low MPE hosts, the oxide ones are more favored owing to their excellent stability and easy synthesis. In this work, the optical and spectroscopic properties of BaGd2O4:Er3+ phosphor were studied. The MPE of BaGd2O4 host was observed from Eu3+ phonon sideband (PSB) spectrum and Raman spectrum to be 477 cm−1 which does not second to the fluoride hosts. The refractive index, which is indispensable for Judd–Ofelt calculation, was confirmed from the both approaches of the Eu3+‐probe and the band gap energy, and the similar refractive indices were confirmed, therefore the average refractive index 2.01 was used in the Judd–Ofelt calculation. The Judd–Ofelt parameters of Er3+ in BaGd2O4 host was confirmed to be Ω2${\Omega _2}\;$= 7.91 × 10−21 cm2, Ω4${\Omega _4}\;$= 2.36 × 10−21 cm2, and Ω6${\Omega _6}\;$= 9.00 × 10−22 cm2. Furthermore, the internal quantum efficiencies for 4F9/2 and 4IJ (J = 9/2, 11/2, and 13/2) levels were determined. Finally, the optical temperature sensing properties were studied in detail, and the temperature calibration curve was experimentally derived, meanwhile the maximum absolute sensitivity was confirmed to be 0.0028 K−1. [ABSTRACT FROM AUTHOR]

Quaternary oxysulfide semiconductors with a formula of MZnOS (M = Ca, Sr, or Ba) have recently attracted a lot of attention as host materials for luminescent dopant ions. Among these oxysulfides, the BaZnOS remains largely unexplored for luminescence in comparison with the CaZnOS and SrZnOS counterparts. This study describes a highly efficient and repeatable synthesis of BaZnOS microcrystals comprising a variety of lanthanide and transition metal ions. Spectroscopic investigations reveal a host‐sensitized luminescence in the dopant ions that display distinct temperature dependence of emission intensity. Accordingly, a class of BaZnOS crystals doubly doped with Pr3+ and Mn2+ is further constructed, which shows a sensitive switching of luminescence color in response to temperature change. The advances in these luminescent nanomaterials offer exciting opportunities for temperature sensing (relative sensitivity of 8.58% K–1) and electrochromism applications. [ABSTRACT FROM AUTHOR]

Pyroxene‐type phosphors were widely developed due to the advantages of high chemical stability, luminous efficiency, and low production cost. In this contribution, a series of Eu2+/Tb3+ co‐doped Ca0.75Sr0.2Mg1.05Si2O6 (CSMS) phosphors with pyroxene structure were successfully synthesized by the solid‐state method. Under the 340 nm excitation, the emission peaks of the phosphor show a redshift with the increase of Eu2+ concentration. The emitting color of Eu2+/Tb3+ co‐doped samples shows a redshift attributed to the energy transfer from Eu2+ to Tb3+. Simultaneously, acquired thermometer exposes superbly temperature‐sensitive properties (Sa and Sr having maximum values 4.7% K−1 and 0.6% K−1, respectively) over the cryogenic temperature range (77–280 K). Furthermore, it has good stability and precision at cryogenic temperatures, indicating that CSMS:0.03Eu2+/0.03Tb3+ phosphor is a very promising fluorescent material suitable for cryogenic temperature sensing. [ABSTRACT FROM AUTHOR]

In recent years, rare earth ions doped optical materials have been extensively utilized in anticounterfeiting, temperature measurement, and other fields. However, it is difficult for single‐mode photoluminescence to meet the increasingly complex anticounterfeiting needs in practice. In this article, Yb3+/Er3+ codoped Y2WO6 multifunctional microparticles have been designed and prepared, which can emit multimode luminescence and are used for anticounterfeiting and temperature measurement. Under excitation at 254, 365, and 980 nm, Y2WO6:Yb3+/Er3+ microparticles can emit blue, green, and yellow‐green luminescence, respectively. The multicolor emission is helpful to improve the security of anticounterfeiting in multimode. In addition, the upconversion, downconversion luminescence, and downconversion lifetime attenuation of this material can be used for fast responsive and noncontact temperature measurement. Among the three temperature measurement methods, the material has the highest sensitivity under the downconversion temperature measurement method, which is 1.25 × 10–2 K–1 (at 303 K). The results suggest that the Y2WO6:Yb3+/Er3+ microparticles have excellent applications in the domain of multimode anticounterfeiting and temperature measurement. [ABSTRACT FROM AUTHOR]

Organic persistent luminescent materials attract great attention, but most of them exhibit single luminescence color with one emission band, which limits their applications in optoelectronic, sensing, and bioimaging fields. Herein, an effective strategy to achieve dual persistent emission is proposed by utilizing the triplet excited state in the single‐molecule 6,12‐diphenyl‐5,6,11,12‐tetrahydroindolo[3,2‐b]carbazole derivatives. Experimental data and theoretical calculations suggest that the triplet excited state operates as a triplet exciton reservoir to stockpile and provide long‐lived excitons for room temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) in aggregate state. Moreover, tunable emission color is achieved through the regulation of RTP and TADF emission by introducing aromatic and aliphatic bromine atoms. Finally, dual persistent emission with a long lifetime of 0.26 s and a persistent luminescence quantum yield of 10% is obtained in single‐component materials, and these luminophores are used for visual temperature detection and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]