Luminescence Yield Research Articles

The interplay between structural features and the efficiency of the energy transfer process in terbium complexes with triarylcyclopentadienyl ligands

Terbium and gadolinium complexes with triarylcyclopentadienyl ligands having electron-donating methoxy substituents in the ortho- (CpPh2Ar−o) and para- (CpPh2Ar−p) positions of one of the phenyl rings have been synthesized. Different structural types, including tetranuclear [{CpPh2Ar−oTb (THF)}2 (μ2-Cl)2(μ3-Cl)3K (THF)]2 (Tb1), [{CpPh2Ar−oTb}2 (μ2-Cl)2 (μ3-Cl)3K]2 (Tb3), [{(CpPh2Ar−oTb)2 (μ2-Cl)3}2 (μ2-Cl)2] (Tb5), [{CpPh2Ar−pTb (THF)}2 (μ2-Cl)2 (μ3-Cl)3K (THF)]2 (Tb6), binuclear [{CpPh2Ar−oTb (THF)Cl}2 (μ2-Cl)2] (Tb4), [{CpPh2Ar−pTb (THF)}2 (μ2-Cl)2 (μ3-Cl)3K (THF)]2 (Tb7), [CpPh2Ar−p2Tb (μ2-Cl) (μ3-Cl)K]2 (Tb8) and mononuclear [CpPh2Ar−o2TbCl] (Tb2) complexes have been obtained and confirmed by single crystal X-ray diffraction analysis. All designed terbium complexes exhibit high quantum yields of the photoluminescence (up to 65 %). The introduction of a methoxy group into one of the phenyl rings of the triarylcyclopentadienyl ligand leads to a more than twofold increase in the quantum yield of the terbium ion luminescence. The estimated values of radiative rate krad of the terbium ion vary in the range of 0.23–0.69 ms. The presence of the methoxy group as well as the mutual disposition of the phenyl rings promotes the appearance of an intraligand charge transfer states involved in the energy transfer process. Due to a lowering of the energy of the interconfigurational 4f −5d transitions caused by the relatively strong crystal field of the Cp ligand in bis(cyclopentadienyl) terbium complexes, the quantum yield of the photoluminescence is high at the short lifetimes of the 5D4 level of the terbium ion.

Regulating the Surface State of Carbon Dots as Ultrahigh-Capacity Adsorbents for Water Treatment.

Adsorption is one of the most widely researched and highly effective methods for mitigating the environmental threat posed by recalcitrant dyes in aqueous solutions. This paper presents a solvent-free synthesis method for the rapid and large-scale production of nitrogen (N) and phosphorus (P) co-doped carbon dots (N, P-CDs) which possess specific surface states and outstanding dye adsorption properties. Compared to the undoped CDs, the N, P-CDs not only exhibit a higher yield of solid-state luminescence but also endow them with the efficient adsorption and removal of Congo red (CR) from water. Due to the synergistic effects of π-π stacking, hydrogen bonding and electrostatic attraction, the N, P-CDs exhibit an ultra-high adsorption capacity (3118.87mgg-1) and a removal efficiency (97.4%, at 500mgL-1) for CR, and also display excellent selective adsorption in both single-dye and dual-dye systems. This method offers a rational strategy for synthesizing novel CDs-based adsorbents for CR, which provides a demonstration for future dye adsorption studies and practical wastewater treatment applications of CDs.

Structural and luminescent properties of YSZ-YSH based ceramics depending on Zr/Hf ratio

Samples of crystalline cubic phased ceramics based on (Zr1-хHfх)0.82Y0.17Eu0.01O1.91 with different contents of hafnium (х = 0; 0.21; 0.50; 0.77; 1) were synthesized. The synthesis conditions were chosen to avoid the possible formation of a minor tetragonal phase. The average grain size was 2–5 microns. The structural parameters of ceramics, their band gap, luminescent and thermoluminescent properties were studied depending on the hafnium content. It was shown that single-phase sample with calculated formula ((Zr0.77Hf0.23)0.82Y0.17Eu0.1)O1.91 demonstrated the highest cathodoluminescent intensity upon excitation by electrons. It was found that thermoluminescent properties of ceramics with hafnium content of х = 0.50–0.77 range are prospective for application in thermodosimetry. The highest luminescence yield was observed in such samples.

Luminescence enhancement of carbon dots synthesized by intense CW laser at 450 nm irradiating biocompatible solutions

Carbon dots (CDs) were synthesized by a continuum wave (CW) laser system irradiating vegetable charcoal placed in a Phosphate-Buffered Saline (PBS) solution. The laser operates at 450 nm with an output power of 50 W and 1 mm2 spot size, irradiating the carbon target for 1–3 h. The used charcoal consists of amorphous carbon that gives rise to CDs in liquids revealing high luminescence in the blue region. The formation of CDs is due to photo-thermal and photo-chemical effects induced by the prolonged laser irradiation inducing carbon atom ejection, scissions, radical formation, chemical bond breaking, molecular detachment bounded by weakened bonds and van de Walls forces, and nanoparticle functionalization in the used solution. The measurements have been concerned with the laser ablation yield, the Fourier Transmission Infrared (FTIR) spectroscopy, the UV-Vis optical spectroscopy, and the luminescence yield induced by UV excitation lamp at 365 nm wavelength. The main luminescence peak is observed at about 480 nm, characteristic of the blue color, with less significant involvement of the near regions at about 450 nm and 520 nm. Results suggest that CDs luminescence can be enhanced by the laser irradiation time, the PBS concentration, and the addition of acetic acid in the PBS solution. The presented luminescence in biocompatible solutions found many applications in different scientific fields. Overall, it is discussed its application for bioimaging in the biomedical field.

Solid solutions in EuSc3(BO3)4-GdSc3(BO3)4 system: Phase diagram, synthesis, crystal growth, structure and luminescence

Solid solutions based on (Eu,Gd)Sc3(BO3)4 (C2/c) and Gd0.25Sc0.75BO3 (R3¯) in the EuSc3(BO3)4-GdSc3(BO3)4 system were studied. Synthesis at 1250 °C provides wide homogeneity regions which are stable at room temperature. Melt-solution crystallization of both compounds from LiBO2-LiF flux was shown. All the obtained samples have luminescence characteristic of Eu3+ with a largest peak at 615 nm corresponding to the 5D0 → 7F2 transition. In this series the luminescence intensity monotonically increases with an increase of Eu content. The largest quantum yield of luminescence (53 %) in the EuSc3(BO3)4-GdSc3(BO3)4 system is demonstrated by EuSc3(BO3)4 sample.

Amplification of interlayer exciton emission in twisted WSe2/WSe2/MoSe2 heterotrilayers

Van der Waals heterostructures based on transition metal dichalcogenides exhibit physical properties that depend on their monolayer constituents’ twisting angle and stacking order. Particularly in type-II heterostructures, low-energy photoluminescence is dominated by interlayer excitons, resulting in low emission yields, which drastically hampers their optoelectronic applicability. This study reports on the photoluminescence quantum yield of heterostructures consisting of WSe2/WSe2/MoSe2 twisted layers. Our findings show that the additional WSe2 monolayer in the trilayer system enhances the low-energy photoluminescence by more than an order of magnitude depending on the WSe2/WSe2 twist-angle in comparison to their WSe2/MoSe2 heterobilayer counterpart. Furthermore, combining density functional theory calculations and extracted degree of circular polarization, we identify excitonic signatures arising from hybridized states that originate from the additional WSe2 layer. In addition to providing an additional understanding of hybridization effects in 2D semiconducting heterostructures, our findings provide a viable method to enhance emission in van der Waals heterostructures, relevant for studying the fundamental properties of excitons and enabling optoelectronic applications with high luminescence yield.

Recent development of luminescent chemosensors for the recognition of nitroexplosives based on zinc(II) Schiff base complexes

In this review, we briefly summarize the key aspects of the synthetic strategies for zinc(II) Schiff base complexes, focusing on their photophysical properties such as the origin of luminescence, intensity, lifetime, and quantum yield. Additionally, we discuss the advantages of using luminescent zinc(II) complex-based sensors, the factors underlying their effectiveness as chemosensors for explosive detection, their mechanisms of action, and future outlooks and concerns. Most of the zinc(II) Schiff base complexes reported to date function as turn-off luminescent chemosensors for nitroexplosives. Some zinc(II) complexes discussed in this review demonstrate very high selectivity and sensitivity, with limits of detection (LOD) in the ppb or nM range for picric acid. Additionally, certain zinc(II) complexes can detect picric acid in the solid state through a visible color change observable to the naked eye under ambient light.

Designed fluorescence "on-off-on" probe based on cobalt, zinc, and nitrogen co-doped graphene quantum dots: A case of quinalphos sensing.

In this study, we developed a new fluorescence "on-off-on" sensor utilizing water-soluble cobalt/zinc-nitrogen co-doped graphene quantum dots (Co/Zn-N-GQDs) to recognize quinalphos pesticide in vegetable and fruit samples. Primarily, the synthesis method employed a one-pot hydrothermal approach, using betel leaves as a natural precursor and cobalt ("Co"), zinc ("Zn"), and urea ("N") as dopant sources. The Co/Zn-N-GQDs probes underwent comprehensive analytical characterization. The Co/Zn-N-GQDs were synthesized with a remarkable luminescence yield of 31.49%, exhibiting excitation at 320 nm and emission peak at 393 nm. Interestingly, the luminescence of Co/Zn-N-GQDs was selectively "Turned Off" by Cu2+ via a static quenching setup. Remarkably, quenched fluorescence was surprisingly reactivated upon adding quinalphos to the quench setup, indicating a direct correlation between luminescence reactivation and quinalphos concentration. Briefly, this phenomenon is ascribed to the functional groups in quinalphos, such as quinoxalinyl and phosphorothioate, which chelate with Cu2+ ions, disrupting the nonfluorescent Cu2+-Co/Zn-N-GQDs complex. The design sensor demonstrated a limit of detection (LOD) of 0.11 μM and a broad linear span of 0.5 to 200 μM. In conclusion, Cu2+-Co/Zn-N-GQDs sensor showed immediate applicability, stability, and reproducibility, making it highly effective for quinalphos sensing in various samples.

Strain‐Insensitive Pre‐Stretch‐Stabilized Polymer/Gold Hybrid Electrodes for Electrochemiluminescent Devices

AbstractThe quest for stretchable properties is at the forefront of research dedicated to on‐skin light–emitting devices. Inspired by the natural wonders of bioluminescence, electrochemiluminescent devices (ECLDs) are distinguished by straightforward design and reduced operating voltage, marking a departure from traditional current‐driven electroluminescent devices (ACELDs). The primary challenge of fully‐stretchable ECLDs lies in crafting electrodes that simultaneously satisfy the demands for conductivity, transparency, stretchability, oxidation resistance, and interface stability. This research introduces a groundbreaking wrinkled polymer‐gold composite electrode. It extends to 50% stretchability, offers outstanding conductivity at 10 Ω sq−1, achieves transparency above 60%, and withstands over 10 000 stretching cycles. Employing this material, alongside stretchable electrospinning fiber luminescent layers, enabled the creation of fully‐stretchable ECLDs. These devices not only shine brightly at 30 Cd m−2 but also retain more than 90% of luminosity when stretched up to 50%. Furthermore, this work has engineered stretchable devices featuring singular patterns and multi‐dot arrays. They exhibit consistent luminescent output under bending, twisting, and stretching when applied to skin. These findings not only highlight the potential of polymer‐gold composite electrodes in overcoming challenges faced by stretchable electronic devices but also provide new ideas for wearable technology that seamlessly integrates with human body.

Europium‐Activated Perovskite Cubical SrZrO3 Red Phosphor: Synthesis, Characterization, and Sustainable Applications in PC‐LEDs and Environmental Forensic Analysis

AbstractA series of SrZrO3 : Eu3+ nano phosphors synthesized by a modified high‐temperature solid‐state reaction method. The structural, functional vibration groups, optical, morphological, luminescence and quantum yield studies were characterized through XRD, FTIR, UV, ‘SEM & HR‐TEM’ and PL analyses respectively. The SrZrO3 : Eu3+ phosphor has a perovskite orthorhombic structure and emits intense red emission around 612 nm when it is excited under 465 nm and covers NUV light range. The calculated average lifetime indicates the nature of the allowed emission transition in Eu3+ (2.44 μs). The calculated colour purity and Commission International del’ Eclairagethe (CIE) chromaticity coordinates are 97.9 % and (0.5894, 0.4031) respectively. The observed quantum yield and thermal stability for the SrZrO3 : Eu3+ (9 mol %) phosphor are 22 % and 87 % at 423 K, respectively. These obtained results suggest that SrZrO3 : Eu3+ (9 mol %) phosphor would meliorate for red‐emitting phosphor in profound RGB‐based pc‐WLED applications.

Engineering the luminescence and photothermal properties of metal complex Ruphen functionalized with silver nanoparticles for infrared human detection

A luminescence quenching enhanced infrared (IR) detector has been developed to achieve highly sensitive recognition of human body by adding metallic luminescence quenchers. Spherical Ag NPs were mixed with Ru(phen)32+ complex to obtain temperature-sensitive Ag/Ruphen/PVDF films. The relationships among luminescence output, temperature rise and silver addition were investigated and a satisfactory combination of enhanced luminescence factor and temperature change was found with an addition of 5 mol% of 71 nm Ag NPs. It is found that the metal-enhanced luminescence output is insignificant compared to its thermal ingredient since silver provides additional possible electron transfer channels, promoting non-radiative transitions and weakening luminescence. Besides, the Ag NPs induced additional temperature rise bringing further reduction of luminescence. The photothermal effect of Ag NPs can attain a higher temperature change under a certain IR radiation without an observed degradation of luminescence output. A coupled optical-thermal model was established to explain the schematic of the constructed infrared thermal detector. The non-invasive detections of moving and stationary human by the detector were successfully demonstrated. The work tends to provide an engineered optical-thermal model in luminophores and construct highly sensitive luminescence-based infrared thermal detectors.

Integrating K+ into Eu and Tb doped GdCa4O(BO3)3: A dual study on photoluminescence and structure

In this study, we investigate the structural and photoluminescence (PL) properties of rare-earth-doped GdCa4O(BO3)3 (GdCOB) phosphors, specifically focusing on the spectral behaviour induced by doping with Eu³⁺ and Tb³⁺ ions. The powder X-ray diffraction (XRD) spectra confirm the formation of a monoclinic phase. The XRD data were also refined by a Rietveld refinement method. The existence of B, O, Ca, Gd, Tb, Eu and K elements was verified by EDS spectra. We introduce a detailed examination of the charge compensation process using Kröger-Vink notation to clarify the mechanisms essential for tailoring the optical properties of the phosphors. The PL excitation spectrum of GdCOB:Eu3+, monitored at 611 nm, reveals sharp excitation peaks at 319, 361, 380, and 392 nm, corresponding to 7F0→5H3, 7F0→5D4, 7F0→7F0, and 7F0→5L6 transitions, respectively. The PL spectrum under excitation of 392 nm exhibits that phosphors doped with Eu3+ a significant red emission at 611 nm, which is attributed to the 5D₀→7F₂ transition. This emission intensity is particularly enhanced at non-centrosymmetric sites of the Eu³⁺ ions. Similarly, the PL excitation spectrum of GdCOB:Tb3+, monitored at 552 nm, displays distinct excitation peaks at 316, 341, 353, and 379 nm, which correspond to the transitions 7F₆→5D₀, 7 F₆→5L₇, 7F₆→5D₂, and 7F₆→5D₃, respectively. Tb³⁺-doped phosphors display a bright green emission, with a dominant peak at 552 nm, resulting from the 5D₄→7F₅ transition. Additionally, the introduction of K⁺ ions as co-dopants results in modifications to the local environments of Eu³⁺ and Tb³⁺ ions. These changes allow for fine-tuning of the emission peaks, significantly enhancing the luminescent output of the phosphors. Optimal doping concentrations of 5 mol% for Eu³⁺ and 1 mol% for Tb³⁺ enhance luminescent intensity and prevent concentration quenching. This phenomenon, often resulting in reduced PL intensity at higher dopant levels, is primarily due to dipole-dipole interactions, consistent with Dexter's theory of energy transfer. Strategic modulation of doping concentrations, coupled with a deep understanding of energy transfer mechanisms are critical for the development of advanced luminescent materials Our analysis of the Commission de l′Eclairage (CIE) chromaticity coordinates reveals enhanced energy transfer dynamics in rare-earth-doped borates, facilitating the tuning of luminescent properties. These results not only deepen our understanding of the fundamental physics governing such phosphors but also open pathways for the development of optoelectronic applications requiring consistent color output, such as LED technologies and solid-state lighting.

Self-Powered and Self-Recoverable Multimodal Force Sensors Based on Trap State and Interfacial Electron Transfer.

Multi-dimensional force sensing that combines intensity, location, area and the like could gather a wealth of information from mechanical stimuli. Developing materials with force-induced optical and electrical dual responses would provide unique opportunities to multi-dimensional force sensing, with electrical signals quantifying the force amplitude and the luminescence output providing spatial distribution of force. However, the reliance on external power supply and high-energy excitation source brings significant challenges to the applicability of multi-dimensional force sensors. Here we reported the mechanical energy-driven and sunlight-activated materials with force-induced dual responses, and investigated the underlying mechanisms of self-sustainable force sensing. Theoretical analysis and experimental data unraveled that trap-controlled luminescence and interfacial electron transfer play a major role in force-induced optical and electrical output. These materials were manufactured into pressure sensor with renewable dual-mode output for quantifying and visualization of pressures by electrical and optical output, respectively, without power supply and high-energy irradiation. The quantification of tactile sensation and stimuli localization of mice highlighted the multi-dimensional sensing ability of the sensor. Overall, this self-powered pressure sensor with multimodal output provides more modalities of force sensing, poised to change the way that intelligent devices sense with the world.

Self‐Powered and Self‐Recoverable Multimodal Force Sensors Based on Trap State and Interfacial Electron Transfer

AbstractMulti‐dimensional force sensing that combines intensity, location, area and the like could gather a wealth of information from mechanical stimuli. Developing materials with force‐induced optical and electrical dual responses would provide unique opportunities to multi‐dimensional force sensing, with electrical signals quantifying the force amplitude and the luminescence output providing spatial distribution of force. However, the reliance on external power supply and high‐energy excitation source brings significant challenges to the applicability of multi‐dimensional force sensors. Here we reported the mechanical energy‐driven and sunlight‐activated materials with force‐induced dual responses, and investigated the underlying mechanisms of self‐sustainable force sensing. Theoretical analysis and experimental data unraveled that trap‐controlled luminescence and interfacial electron transfer play a major role in force‐induced optical and electrical output. These materials were manufactured into pressure sensor with renewable dual‐mode output for quantifying and visualization of pressures by electrical and optical output, respectively, without power supply and high‐energy irradiation. The quantification of tactile sensation and stimuli localization of mice highlighted the multi‐dimensional sensing ability of the sensor. Overall, this self‐powered pressure sensor with multimodal output provides more modalities of force sensing, poised to change the way that intelligent devices sense with the world.

Behavior of Microstrain in Nd3+-Sensitized Near-Infrared Upconverting Core-Shell Nanocrystals for Defect-Induced Tailoring of Luminescence Intensity.

In an attempt to optimize the upconversion luminescence (UCL) output of a Nd3+-sensitized near-infrared (808 nm) upconverting core-shell (CS) nanocrystal through deliberate incorporation of lattice defects, a comprehensive analysis of microstrain both at the CS interface and within the core layer was performed using integral breadth calculation of high-energy synchrotron X-ray (λ = 0.568551 Å) diffraction. An atomic level interpretation of such microstrain was performed using pair distribution function analysis of the high-energy total scattering. The core NC developed compressive microstrain, which gradually transformed into tensile microstrain with the growth of the epitaxial shell. Such a reversal was rationalized in terms of a consistent negative lattice mismatch. Upon introduction of lattice defects into the CS systems upon incorporation of Li+, the corresponding UCL intensity was maximized at some specific Li+ incorporation, where the tensile microstrain of CS, compressive microstrain of the core, and atomic level disorders exhibited their respective extreme values irrespective of the activator ions.

Dependence of the quantum yield of upconversion luminescence emitted by powdered NaYF4:Yb,Er samples on ytterbium-ion content and excitation intensity

Subject of study. This study investigated a series of powdered NaYF4:Yb,Er samples with varying ytterbium-ion contents. Aim of study. This study aimed to determine the change in the quantum yield of upconversion luminescence exhibited by NaYF4:Yb,Er as a function of the ytterbium-ion content and intensity of excitation by laser irradiation at a wavelength of 975 nm. Method. The quantum yield of upconversion luminescence was determined using a spectrometer and an integrating sphere. Main results. The quantum yield of upconversion luminescence was measured for a series of powdered NaYF4:Yb,Er samples with different ytterbium-ion contents. The optimal ytterbium-ion content, corresponding to the maximum efficiency of upconversion, was found to be 0.4 at%. Practical significance. The results obtained can be applied in optoelectronics, medicine, and the development of laser facilities.

The temperature dependent optical and scintillation characterisation of Bridgman grown CsPbX[formula omitted] (X = Br, Cl) single crystals

Lead halide perovskites are reportedly a very promising group of materials for scintillation due to their fast sub-nanosecond exciton luminescence, small band-gaps, and high theoretical light yield. Unfortunately, they only show emission at cryogenic temperatures. In this work single crystals of CsPbBr3 and CsPbCl3 are studied at cryogenic temperatures. Upon comparing the 10 K emission spectra measured under X-ray and UV–vis excitation, a new near-infrared emission was found for both CsPbBr3 and CsPbCl3 only present under X-ray excitation. The integral light yields of CsPbBr3 and CsPbCl3 at 10 K are estimated to be 34,000 and 2,200 photons/MeV under 40 keV X-ray excitation, respectively. The main components of the light yield of CsPbBr3 at 10 K are the near band-gap free exciton emission that suffers from self-absorption and the broad near-infrared emission that falls outside the typical detection range of a photo-multiplier tube. Due to the combination of the two aforementioned effects it was not possible to measure a γ-ray pulse height spectrum for CsPbBr3 at 10 K. Despite all the suitable properties, like the fast decay, a small band-gap, and the positive prospects of 3D perovskite based scintillators, we conclude that these materials perform poorly as scintillation crystals.

Isochemical crystallization in condensed borate LaMgB5O10 glass-ceramics doped with optical probe Eu3.

The isochemical glass-ceramics doped with Eu3+ were prepared by the heat treatment of lanthanum magnesium borate glass. The crystalline phase was chemically identical to a glass matrix and consisted of condensed borate LaMgB5O10. The isochemical crystallization process begins with the formation of rings by BO4 groups. The emergence of ordered crystalline phase gives rise to intense charge transfer absorption of Eu3+, allowing the efficient luminescence under UV. The analysis of Judd-Ofelt parameters and comparison to purely crystalline samples obtained by solid-state synthesis reveal a switch of parameter relations from Ω2 > Ω4 for glass to Ω2 < Ω4 for crystals but also a maximum value of Ω6 for glass-ceramic sample, which indicates enhanced structural rigidity and results in superior luminescence output. The quantum yield measurements confirmed higher luminescence efficiency for glass-ceramics compared to both pure glass and pure crystalline samples.

Overcoming Thermal Quenching in X‐ray Scintillators through Multi‐Excited State Switching

AbstractX‐ray scintillators have gained significant attention in medical diagnostics and industrial applications. Despite their widespread utility, scintillator development faces a significant hurdle when exposed to elevated temperatures, as it usually results in reduced scintillation efficiency and diminished luminescence output. Here we report a molecular design strategy based on a hybrid perovskite (TpyBiCl5) that overcomes thermal quenching through multi‐excited state switching. The structure of perovskite provides a platform to modulate the luminescence centers. The rigid framework constructed by this perovskite structure stabilized its triplet states, resulting in TpyBiCl5 exhibiting an approximately 12 times higher (45 % vs. 3.8 %) photoluminescence quantum yield of room temperature phosphorescence than that of its organic ligand (Tpy). Most importantly, the interactions between the components of this perovskite enable the mixing of different excited states, which has been revealed by experimental and theoretical investigations. The TpyBiCl5 scintillator exhibits a detection limit of 38.92 nGy s−1 at 213 K and a detection limit of 196.31 nGy s−1 at 353 K through scintillation mode switching between thermally activated delayed fluorescence and phosphorescence. This work opens up the possibility of solving the thermal quenching in X‐ray scintillators by tuning different excited states.

Overcoming Thermal Quenching in X-ray Scintillators through Multi-Excited State Switching.

X-ray scintillators have gained significant attention in medical diagnostics and industrial applications. Despite their widespread utility, scintillator development faces a significant hurdle when exposed to elevated temperatures, as it usually results in reduced scintillation efficiency and diminished luminescence output. Here we report a molecular design strategy based on a hybrid perovskite (TpyBiCl5) that overcomes thermal quenching through multi-excited state switching. The structure of perovskite provides a platform to modulate the luminescence centers. The rigid framework constructed by this perovskite structure stabilized its triplet states, resulting in TpyBiCl5 exhibiting an approximately 12 times higher (45 % vs. 3.8 %) photoluminescence quantum yield of room temperature phosphorescence than that of its organic ligand (Tpy). Most importantly, the interactions between the components of this perovskite enable the mixing of different excited states, which has been revealed by experimental and theoretical investigations. The TpyBiCl5 scintillator exhibits a detection limit of 38.92 nGy s-1 at 213 K and a detection limit of 196.31 nGy s-1 at 353 K through scintillation mode switching between thermally activated delayed fluorescence and phosphorescence. This work opens up the possibility of solving the thermal quenching in X-ray scintillators by tuning different excited states.