Dual Emission Research Articles

Luminescence properties of Sr2Ga2GeO7:Bi3+ phosphors and temperature sensing characteristics of co-doped Sm3.

As one of the fundamental physical quantities, temperature is extremely important in various fields. In order to study the temperature sensing characteristics of dual-emitting center phosphors, Bi3+-doped and Bi3+/Sm3+-doped Sr2Ga2GeO7 phosphors were synthesized by high-temperature solid-phase method. Under 312 nm excitation, the Sr2Ga2GeO7:Bi3+ phosphor exhibits a blue broadband emission corresponding to the 3P1 → 1S0 transition of Bi3+ ions. By testing the temperature change spectrum of phosphors, it was found that Bi3+ exhibited strong thermal sensitivity. However, due to the fact that single ion doped phosphors are easily affected by other factors when applied to the field of temperature sensing, based on the thermal sensitivity of Bi3+, Sm3+ with low temperature sensitivity was selected as the co-doped ion, and it was found that the two ions had different thermal quenching characteristics when the temperature change spectrum was tested. Using the temperature detection method based on the fluorescence intensity ratio (FIR) of the dual emission centers, it was found that the best absolute sensitivity Sa was 3.125% K-1 and the maximum relative sensitivity Sr was 1.275% K-1 in the range of 303-423 K. These results show that Sr2Ga2GeO7:Bi3+/Sm3+ phosphors have broad application prospects in the field of optical temperature sensing.

Controllable Preparation of a Cu NCs@Zn-MOF Hybrid with Dual Emission Induced by an Ion Exchange Strategy for the Detection of Explosives.

The precise synthesis of Cu NCs is a highly desirable and controllable route for the preparation of desired structures and properties, which facilitates the rational design of valuable probes for fluorescence sensing and the understanding of structure-property relationships. Herein, an ion-exchange strategy combined with a bottom-up synthetic approach was utilized in the synthesis process of Cu NCs for the first time, which achieved the controllable synthesis of Cu NCs and in situ anchoring of Cu NCs on the support material HPU-14. The as-prepared Cu NCs@HPU-14-4h not only had a good peroxidase-like property but also exhibited stable dual-emitting fluorescence at 470 and 620 nm. Notably, the peroxidase-like property endowed Cu NCs@HPU-14-4h with the capability of highly sensitive colorimetric detection of H2O2 in a linear concentration from 0.1 to 140 μM (detection limit of 86.7 nM), and a change in the fluorescent color from red to blue could be observed by the naked eye. Furthermore, due to the large overlap between the absorption of 2,4,6-trinitrophenol (TNP) and the excitation band of Cu NCs@HPU-14-4h, TNP could also be detected from 27 types of analogs and common ions with a limit of detection of 68 nM. Finally, a portable hydrogel probe with efficient wipe sampling was fabricated by polyvinyl alcohol (PVA) comprising Cu NCs@HPU-14-4h with the aim of on-site visualization of different explosives. Consequently, the current study not only provides a new idea for the precise synthesis of Cu NCs and their controllable anchoring on support materials but also offers an effective method for predicting H2O2 and TNP.

Dual-emission rare-earth fluorescent nanomaterials for ratiometric and visual detection of N-acetylneuraminic acid and applications in information encryption and anti-counterfeiting

N-acetylneuraminic acid (NANA) can be used as a biomarker for many types of cancers. Currently, there are various methods for detecting NANA but showing some shortcomings that limit the real-time diagnosis of cancer. In contrast, fluorescence analysis has obvious advantages such as low cost, fast response time, and easy operation, and it also enables visual detection for real-time cancer monitoring. Therefore, the establishment of an efficient and rapid detection method is essential for the early prevention and treatment of the disease. Based on the properties of layered rare-earth hydroxide (LRH), we synthesized a dual-emission fluorescent material (NDC/SDS-LEuH), and further fabricated a fluorescent nanoprobe (ANP) for the detection of NANA. The probe has the advantages of high sensitivity (LOD = 32.9 μM) and high selectivity with fast response. During the sensing process, the dual emission of the probe shows opposite changes due to the photoinduced electron transfer (PET) effect and the interaction between NANA and the probe. The color changes of the system can be observed under UV irradiation. Therefore, a visual platform was developed to detect NANA with a LOD of 0.09 mM. In addition, a probe hydrogel was prepared, which can be applied in the anti-counterfeiting to improve the difficulty of counterfeiting and the security of anti-counterfeiting. The probe achieves ratiometric fluorescence detection of NANA, which reduces background interference and improves the accuracy of detection. A visual detection platform was fabricated to realize the real-time detection. In addition, the prepared probe hydrogel showed the potential applications in anti-counterfeiting, which provided new ideas for the design and application of anti-counterfeiting materials.

Regulation of TADF and RTP Dual Emission via Internal and External Heavy-Atom Effects.

Organic materials with thermally activated delayed fluorescence (TADF) and room-temperature phosphorescence (RTP) dual emission have attracted great attention in recent years, but the regulation mechanism via internal and external heavy atoms is not clear enough. Here, we carry out a systematic theoretical investigation on the photophysical properties of the materials by introducing aliphatic or aromatic bromine atoms. The molecule with aromatic bromine atoms exhibits obvious TADF owing to the effective reverse intersystem crossing (RISC) with matchable energy levels and enhanced spin orbit couplings, the molecule with aliphatic bromine atoms shows a long RTP lifetime because of the reduced nonradiative transition of triplet excitons, and the molecule with both aliphatic and aromatic bromine atoms presents balanced TADF and RTP emissions thanks to the synergy internal and external heavy-atom effects. Besides, the internal and external heavy atoms induce multisite intermolecular interactions, effectively suppressing the nonradiative process in the solid phase. The efficient RISC process and the suppressed nonradiative process of triplet excitons should be key to regulating the dual emission property. These findings and insights are of great importance for revealing the structure-performance relationship, providing theoretical guidance for the design of TADF and RTP dual emission molecules via internal and external heavy-atom effects.

Synthesizing, characterizing, and cold plasma treating of Cr2O3/CuO nanomaterials doped PMMA/PEO for flexible optoelectronic applications

Polymeric nanocomposites are attracting significant attention due to their ability to facilitate innovative uses. This work investigated the possibility of improving performance by examining the impact of dispersing copper oxide (CuO) and chromium (III) oxide (Cr2O3) nanoparticles in a blend of poly (methyl methacrylate) and polyethylene oxide (PEO) on several properties. UV–visible and photoluminescence spectroscopies were used for optical properties, and FE-SEM was used for surface morphology analysis. The results showed that as the CuO–Cr2O3 percentage increased, the extinction coefficient increased, and indirect band gaps decreased. The photoluminescence properties showed two distinct peaks (dual emission). We measured the AC electrical properties with frequencies ranging from 100 Hz to 5 MHz. The composite's AC conductivity and dielectric loss increased significantly at high frequencies (higher than 2 MHz). The dielectric constant is nearly frequency-independent and increases as the concentration of nanoparticles increases. We used a DC plasma sputtering facility to treat the nanocomposites with argon plasma at a pressure of 0.12 mBar for 7 min. We analyzed the films' properties before and after plasma treatment, observing a significant impact on nanocomposite-incorporated nanoparticles. After plasma treatment, the band gap decreased from 5.05 eV to 4.8 eV for the lowest concentration of CuO + Cr2O3 (1.5 wt%) and from 3.55 eV to 2.47 eV for the highest concentration of CuO + Cr2O3 (6 wt%). The changes ranged from 0.25 to 1.08 eV. The films possess features that render them suitable for high-frequency optoelectronic devices as well as optical applications such as emission filters and UV shielding.

The dual-band emissions, multicolor continuous mechanochromisms, and application based on a single luminogen

Currently, the high contrast and multicolor continuous mechanochromic materials still face a great challenge. Here, a novel D-π-A type luminogen named as CzIPCN, was successfully constructed. By solvent diffusion method, crystals YC, BT, RE, and RA were obtained, not only covering a large-span emission from blue to red, but also showing scare dual band emission. Interesting, the blue BT and yellow YC have similar intermolecular π-π stacking interactions and significantly different emission maxima, while two emission maxima of the RE and RA appear at the similar frequency but with different intensity ratios. More interesting, emission maxima of BT present tiny shifts before/after grinding, but RE and RA show very low mechanical force thresholds in mechanochromism, and yield significant color contrasts and wavelength shifts (＞100 nm). Under both light&hard crushing and grinding, YC presents multicolor continuous mechanochromism. Additionally, CzIPCN not only shows pH-dependent fluorescence emission but also white light emission in a DCM-TFA mixture. Finally, high-level anti-counterfeiting patterns controlled by different mechanical forces were successfully constructed. It is worth mentioning that this is the first report on multiple anti-counterfeiting patterns using a single luminogen.

Incorporation of ESIPT into pillar[5]arene for solid-state dual emission responsive to n-hexane vapor

Abstract Pillar[5]arene is a promising macrocyclic receptor of a chemical sensor showing shape-selective encapsulation of neutral molecules into the cavity, but the poor fluorescence properties remain a challenge. Herein, we report a pillar[5]arene coupled with 2-(2-hydroxyphenyl)benzoxazole (HBO), which displays bright fluorescence in both solution and the solid state. Owing to the excited-state intramolecular proton transfer (ESIPT) in the HBO moiety, greatly improved fluorescence is observed for the pillar[5]arene derivative in CHCl3 (Φlum = 11%) and powder form (Φlum = 25%). Moreover, the emission color changes from light green to blue when the powder sample is exposed to n-hexane vapor. The color change derives from variable dual emission via ESIPT and excimer-forming pathways, as suggested by fluorescence lifetime measurements at different wavelengths. Powder x-ray diffraction indicates that increased crystallinity and a small alteration in the solid-state structure leads to visible fluorescent chromism upon vapor encapsulation.

Dynamic, multi-color, multi-level stimulus-responsive luminescence in a co-crystallized coordination polymer: Modulation of energy transfer by acid-induced ligand protonation and photo-induced radical generation

Stimulus-responsive luminescent materials (SLMs), which can respond to external stimuli by switching their luminescence properties, hold great promise for a variety of applications. Particularly, multi-level SLMs with a logical stimulus sequence and a dynamic, multi-color transition are highly desirable for anti-counterfeiting and information encryption, but an effective design strategy is lacking. Herein, a co-crystallized coordination polymer multi-level SLM [Cd(9-AC)4]·(HAD)2·(9-HAC)2 (9-HAC for anthracene-9-carboxylic acid and AD for acridine) with dual emission centers of coordination unit ([Cd(9-AC)4]2-) and exciplex ([9-HAC/HAD]+) has been successfully constructed by a stepwise solvent process. This SLM possesses a variety of stimulus-responsive properties, including mechanochromic (MC), mechanochromic luminescence (MCL), reversible acidochromic luminescence (ACL), and reversible photochromic luminescence (PCL). Notably, both ACL and PCL properties are achieved by modulating the energy transfer process between the coordination unit and the exciplex, while there is a logical sequence between these two stimulus actions. The acid-induced activation and radical-regulated PCL performance has been exploited in the development of anti-counterfeiting and information encryption applications. This work provides an effective strategy to realize dynamic, multi-color, multi-level stimuli-responsive luminescence by modulating the energy transfer through acid-induced ligand protonation and photo-induced radical generation.

Design and synthesis of a 2,5-Diarylthiophene chromophore for enhanced near-infrared two-photon uncaging efficiency of calcium ions

The design and synthesis of two-photon-responsive chromophores have recently garnered significant attention owing to their potential applications in materials and life sciences. In this study, a novel π-conjugated system, 2-dimethylaminophenyl-5-nitrophenylthiophene derivatives, featuring a thiophene unit as the π-linker between the donor (NMe2C6H4–) and acceptor (NO2C6H4–) units was designed, synthesized, and applied for the development of two-photon-responsive chromophores as a photoremovable protecting group in the near-infrared region. Notably, the positional effect of the nitro group (NO2), meta versus para position, was observed in the uncaging process of benzoic acid. Additionally, while the para-isomer exhibited a single fluorescence peak, a dual emission was detected for the meta-isomer in polar solvents. The caged calcium ion (Ca2+) incorporating the newly synthesized thiophene unit exhibited a sizable two-photon absorption cross-section value (σ2 = 129 GM at 830 nm). Both one-photon and two-photon photoirradiation of caged calcium ions successfully released calcium ions, indicating the potential utility of 2,5-diarylthiophene derivatives in future biological studies.Graphical abstract

Dual emission BSA-capped bimetallic nanoclusters for detection of acrylamide in certain food matrices based on thiol-ene Michael addition click reaction

Dual-emissive gold and silver nanoclusters stabilized by bovine serum albumin (BSA@Au-Ag NCs) were engineered for the precise and sensitive estimation of acrylamide (ACM). The probe demonstrated emissions at 630 nm and 405 nm upon excitation at 320 nm. Decreasing the fluorescence of the probe at 630 nm was observed upon cysteine (Cys) addition while the emission band at 405 nm experienced a slight increase. The introduction of ACM into the probe led to the recovery of fluorescence at 630 nm, while the fluorescence at 405 nm remained largely unaffected. This selective response provides a ratiometric method for determining ACM. A linear relationship between the response ratio (F630/F405) and ACM concentration was established in the range of 0.12–450 µM, with LOD of 0.03 µM. The fluorescent probe boasts several advantages, including a low LOD, robustness against interference, and reliability. Furthermore, the synthesized probe was deployed for detecting ACM in certain food matrices. The recovery percentages ranged from 96.5 to 102.6 %, with RSD between 2.98 and 4.87 %, thus affirming the potential practical applications of the fluorescent probe.

Realizing Stable Luminescence in Antimony Doped Hybrid Tin(IV) Chloride toward Full Spectrum WLED and Anticounterfeiting Applications.

The outstanding optical properties empower Sb3+-doped zero-dimensional hybrid metal halides as cutting-edge luminescent materials. In this research, we present an efficient hybrid tin chloride, TEA2SnCl6:Sb3+ (TEA = tetraethylammonium), with broad dual emission bands peaking in the blue and orange regions that arise from the singlet and triplet state emissions of [SbCl5]2-, respectively. TEA2SnCl6:Sb3+ demonstrates a high photoluminescence quantum yield (PLQY) of 83.5% under 328 nm excitation, while 358 nm light induces an orange emission with a PLQY of 92.5% and a low thermal quenching behavior (73.9% at 423 K). Benefiting from the appealing luminescence properties of TEA2SnCl6:Sb3+, a full spectrum white light-emitting diode (WLED) device and an anticounterfeiting model were constructed, affirming the potential use of Sb3+-doped TEA2SnCl6 hybrid metal halide in versatile application fields.

White Light Emission from Zn(II) and DMSO-Induced Copper Nanocluster Assembly.

An assembly of metal nanoclusters driven by appropriate surface ligands and solvent environment may engender entirely new photoluminescence (PL). Herein, we first synthesize histidine (His) stabilized copper nanoparticles (CuNPs) and, subsequently, copper nanoclusters (CuNCs) from it using 3-mercaptopropionic acid (MPA) as an etchant. The CuNCs originally emit bluish-green (λem=470 nm) PL with a low quantum yield (QY∼1.8 %). However, it transformed into a dual-emissive nanocluster assembly (Zn-CuNCs) in the presence of Zn(II) salt, having a distinct blue emission band (λem=420 nm) and a red emission band (λem=615 nm) with eight times QY (∼9.1 %) enhancement. The temperature-dependent emission spectra of Zn-CuNCs depicted that the blue emission band persists for all the temperature ranges (0-80 °C) while the red emission band vanishes at high temperatures (70-80 °C). Thus, the blue emission may originate from the locally excited state (LES) emission of the nanoclusters, while the red emission originates from through-space interaction (TSI) and Cu(I)…Cu(I) interaction within the assembly. Adding dimethyl sulfoxide (DMSO) further modifies the emission intensities; the red band was amplified four times, while the blue band was diminished by 2.5 times. The transmission electron microscopy (TEM) images unveiled that the Zn-CuNCs are a large assembly of tiny nanoclusters, which become more compact in DMSO. The blue emission possesses steady-state fluorescence anisotropy, while the red emission shows no anisotropy. Further, near-perfect white light emission(WLE) was rendered with CIE coordinates of (0.33, 0.32) by combining the dual emission of the Zn-CuNCs with the original green emission of the CuNCs.

Ratiometric fluorescence sensing of triclosan by Lanthanide-Functionalized Metal–Organic frameworks

As a widely used antibacterial and antifungal agent in numerous personal care and consumer products, triclosan (TCS) is frequently detected in natural water bodies and has caused serious harm on human health and ecosystems. The quantitative and fast analysis of TCS is thus of paramount significance, however still remains challenging. In recent years, ratiometric fluorescence sensing has attracted vast interests in analyte detection due to the dual emission, which can effectively eliminate interference from environmental factors and improve the detection accuracy. Benefiting from the strong encapsulation capability and structural adjustability, metal organic frameworks (MOFs) are demonstrated to be a perfect platform to construct ratiometric fluorescence sensors. In the present study, we modify a zirconium MOF, UiO-67-bpy, to be a ratiometric fluorescence sensor by introducing Eu3+ and carbon dots sequentially via the post-synthetic method. The obtained hybrid system, CDs@Eu/UiO-67-bpy, shows two well separated emission peaks. With the addition of TCS, the red fluorescence from Eu3+ at 611 nm decreases while the blue fluorescence from carbon dots at 412 nm remains unchanged, resulting an excellent ratiometric response. Linear relationships of the fluorescence ratio (F412/F611) against the concentration of TCS are acquired in both low and high concentration range with detection of limit as low as 0.53 and 2.3 μM, respectively. Moreover, satisfactory recoveries of TCS levels from CDs@Eu/UiO-67-bpy are achieved in various water samples and personal care products. The composite of CDs@Eu/UiO-67-bpy also displays a fluorescence color changing from red to blue responsive to different concentration of TCS, demonstrating great potential in practical application of CDs@Eu/UiO-67-bpy for visualized monitoring TCS.

Gold nanoclusters and amino-modified mesoporous silica-encapsulated carbon dot fluorescence nanosensors combined with LightGBM algorithm for ultra-fast detection of Co2+

In this study, we develop a novel ratiometric fluorescent nanosensor for the detection excess Co2+ in soil. This fluorescent nanosensor is fabricated using mesoporous silica-encapsulated nitrogen-doped carbon dots (N-CDs@mSiO2) and gold nanoclusters stabilized by bovine serum albumin (BSA-AuNCs). The green fluorescence of the carbon dots within the mesoporous silica spheres (mSiO2) serves as an internal reference signal. The red fluoresence BSA-AuNCs are covalently connected onto the surface of amino-functionalized nanospheres (N-CDs@mSiO2-NH2), providing the response signal. This nanosensor has dual emission peaks at 520 nm and 650 nm under excitation wavelength of 380 nm. The addition of Co2+ to this nanosensor causes the fluorescence quenching at 650 nm while the green fluorescence at 520 nm remains unchanged, resulting in fluorescence color change from yellow to green. The developed ratiometric fluorescence nanosensor exhibits excellent selectivity to Co2+ with a range of 2.00–200.00 μM and a detection limit as low as 0.74 μM. In addition, a Co2+ prediction model is developed using the Light Gradient Boosting Machine (LightGBM) algorithm. The entire detection process is within 10 s and the model prediction value is as high as 0.991 on average. This shows that the proposed fluorescent nanosensor, optimized with the LightGBM algorithm, provides an efficient, environmentally friendly and potentially practical solution for Co2+ detection.

Dual Channel Emissions of Kasha and Anti‐Kasha from a Single Radical Molecule

AbstractStable open‐shell luminescent radicals have recently attracted much attention due to their unique luminescence properties. However, a radical molecule with both Kasha and anti‐Kasha doublet emission properties has not been reported. Herein, we have successfully synthesized a stable chlorine‐substituted Chichibabin's hydrocarbon, TTM‐TTM, along with its mono‐radical counterpart, TTM‐HTTM. The emission of TTM‐TTM follows Kasha's rule in the near infrared region. However, TTM‐HTTM shows dual channel doublet emissions of Kasha and anti‐Kasha. Remarkably, these two types of emission compete dynamically in both solution and condensed states. Our findings provide valuable insights into the rational design and discovery of stable radicals that possess distinctive luminescent properties, thus broadening the horizons of luminescent materials research.

Hierarchical Self-Assembly and Aggregation-Induced Emission Enhancement in Tetrabenzofluorene-Based Red Emitting Molecules.

The newly synthesized chiral active [5]helicene-like tetrabenzofluorene (TBF) based highly red-emitting molecules exhibit flower-like self-assembly. These molecules display photophysical and structural properties such as intramolecular charge transfer, dual state emission, large fluorescence quantum yield, and solvatochromism. In TBFID, the indandione functional group attached on both sides as the terminal group offers an A-D-A push-pull effect and acts as a strong acceptor to cause more redshift in solution as well as in solid state as compared to TBFPA (TBF with benzaldehyde functional group in terminal position). The self-assembly studies of TBFID demonstrate the aggregation-induced emission enhancement (AIEE) attributed to the restriction of intramolecular rotation at the aggregated state. Furthermore, TBFID shows high quantum yield and intense red emission, making the molecule fit for organic light-emitting diodes (OLED) and bioimaging applications.

Extrinsic Self‐Trapped‐Exciton Emission in Cs5Cu3Cl6I2 for Efficient X‐Ray Scintillation

AbstractEfficient and stable scintillators play a crucial role in X‐ray detection applications. To enhance the luminescence efficiency under X‐ray excitation, the incorporation of multiple emission centers into scintillators is widely explored. Here, it is found that the cesium copper halide Cs5Cu3Cl6I2 exhibits dual emission centers, enabling high‐performance scintillators with an X‐ray light yield of 49000 photon MeV−1 and a low detection limit of 4 nGy s−1. The emissions of Cs5Cu3Cl6I2 are from intrinsic self‐trapped exciton (STE) and Frenkel defect‐assisted STE. High‐energy X‐rays can induce an increased fraction of Frenkel defect‐assisted STEs, which can serve as an effective scintillation channel. Furthermore, large‐area flexible scintillators with a high resolution of 18 lp mm−1 are developed, making them suitable for X‐ray imaging applications. These findings offer promising insights for developing more efficient scintillators.

Lanthanide metal-organic framework functionalized with 10-hydroxybenzo[h]quinoline for ratiometric sensing to real-time determine monophenolase activity through indicator displacement assay

Tyrosinase monophenolase activity plays a crucial role in various biological processes and industrial applications, making the development of continuous monophenolase assays highly significant. In this study, ratiometric fluorescence sensing using a dual-emission sensor was established to determine monophenolase activity in real-time by integrating indicator displacement assay with lanthanide metal-organic frameworks (MOFs). Europium MOFs functionalized with 10-hydroxybenzo[h]quinoline (HBQ) were fabricated by conjugating an HBQ guest fluorophore to the 3,5-dicarboxyphenylboronic acid (DBA) ligand using a solvothermal method. The conjugated HBQ served as an optical indicator at 510 nm with large Stokes shift, whereas the Eu-MOFs acted as a fluorescent internal standard at 616 nm for dual emission. DBA acts as an antenna ligand and provides a competitive receptor site for L-3,4-dihydroxyphenlalanine (L-DOPA) and HBQ. L-DOPA competitively binds to DBA owing to its higher affinity and displaces the conjugated HBQ, resulting in the quenching of HBQ and Eu-MOFs fluorescence. A linear change in the dual-emission intensity ratio was observed as a ratiometric response towards L-DOPA. The sensor quantified L-DOPA with a detection limit of 0.13 μM. Monophenolase activity was correlated with the real-time change in the ratiometric signal using L-DOPA as the product of the enzymatic reaction. A progression curve for the formation of L-DOPA was constructed to calculate the initial rate, yielding a low detection limit for monophenolase activity of 0.15 U·mL−1. The method has been successfully applied to real samples, kinetic studies, and high-throughput screening of inhibitors. This sensing platform opens a new avenue for determining tyrosinase activity.

Incorporating Sb (III) and Bi (III) ions into Cs2AgNaInCl6 perovskite toward efficient white-light emission with high color rendering index

Single phosphor with efficient and high quality white-light emission is necessary for lighting applications. In this work, we report a double perovskite, Cs2AgNaInCl6 with Bi3+ and Sb3+ incorporation, which demonstrates excellent white-light properties including tunable emission component and correlated colour temperature (CCT). Using the broad-band emission of self-trapped excitons (STEs) associated with Bi3+ and Sb3+ in the Cs2AgNaInCl6 host, the blue and orange dual-band STEs emission located at 460 and 565 nm covers the entire visible range to achieve high-quality white light emission. The relative intensity of the dual emission components can be adjusted flexibly by modulating the doping ratio of Bi3+ and Sb3+. The dual STEs emission shares the same optimal excitation wavelength at 340 nm. The optimal sample of Bi3+ (1 %) and Sb3+ (10 %) codoped Cs2Ag0.1Na0.9InCl6 exhibits high color rendering index (CRI) of up to 93, and high photo-luminescence quantum yield (PLQY) of 76 %. This codoping in double perovskite approach represents a promising method for achieving high-quality white lighting application within a single phosphor.

Thin Ga-doped ZnO Film with Enhanced Dual Visible Lines Emission

Introduction: In this study, a simple and facile route was employed to prepare a highly transparent and luminescent ultra-thin gallium doped ZnO film (GZO). Methods: The thin GZO film has been deposited using the simultaneously ultrasonic vibration and sol-gel spin-spray coating technique. The structural and optical properties of pure and doped thin films were investigated by various methods, such as X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS), scanning electron microscopy (SEM), UV-Vis, and PL spectroscopy. Results: XRD results indicated that both pure and doped ZnO films had a hexagonal wurtzite structure with (101) preferred orientation. XPS and EDX studies confirmed the incorporation and presence of Ga ions into the ZnO lattice structure. The doped sample showed nearly 90% of transparency, and a strong blue-green emission in the visible region. Conclusion: The obtained results proved that the prepared thin film could be a novel candidate for optoelectronic applications.