Quantum Efficiency Research Articles

High Stability and Corrosion-Resistant Gas of Recyclable and Versatile Manganese-Doped Lead-Free Double Perovskite Crystals toward Novel Functional Fabric and Photoelectric Device.

Lead-free halide perovskites possess excellent photoelectric properties, making them widely used in the photoelectric fields. Herein, lead-free double perovskite crystals (PCs) doped with manganese (Cs2NaInCl6:Mn2+) are successfully prepared by the more energy-efficient crystallization method. The crystals emit bright orange-red light under the ultraviolet (UV) lamp, showing unique optical properties. They have the highest photoluminescence quantum yield of 42.91%. The white light-emitting diodes (LEDs) are fabricated using these perovskite crystals, which show a color rendering index of 92 and external quantum efficiency (EQE) as high as 16.3%. Furtherly, perovskite-modified fiber paper made of aramid chopped fibers (ACFs) and polyphenylene sulfide (PPS) exhibited fluorescent properties under different conditions. This paper combines fiber composite technology with PPS fiber filter bags, which are widely used in environmental protection, for the first time and demonstrates functional fiber filter bags with fluorescent characteristics. This filter bag provides an idea for the automatic detection of industrial filtration. Meanwhile, after being exposed to industrial waste gas for 60h, the filter bag can maintain superior fluorescence performance. In this study, lead-free double perovskites are synthesized using an efficient method for preparing high-performance LEDs and high-stability fluorescent fibers. Concurrently, the application of perovskites in environmental protection is expanded.

Penternary Wurtzitic Nitrides Li1-xZnxGe2-xGaxN3: Powder Synthesis, Crystal Structure, and Potentiality as a Solar-Active Photocatalyst.

We developed a new penternary wurtzitic nitride system Li1-xZnxGe2-xGaxN3 (0 ≤ x ≤ 1) by hybridizing LiGe2N3 and ZnGeGaN3. Fairly stoichiometric fine powder samples were synthesized by the reduction-nitridation process at 900 °C. While the end member LiGe2N3 possessed a relatively large band gap of 4.16 eV, the band gap of the developed penternary system varied in a broad range of 3.81 to 3.10 eV, showing promising responsivity to the solar spectrum. The crystal structure of LiGe2N3 was precisely determined by time-of-flight neutron powder diffraction for the first time, revealing the complete ordering of Li and Ge in the Cmc21 structure. The structural evolution from completely ordered LiGe2N3 to fully disordered ZnGeGaN3 was quantitatively analyzed by Rietveld refinement based on a partially disordered Cmc21 model, and the obtained results were also supported by 71Ga solid-state NMR spectroscopy. The synthesized Li1-xZnxGe2-xGaxN3 powder samples exhibited photocatalytic activities for the water reduction and oxidation reactions under solar light irradiation, with the H2 evolution rate of 0.3-59.0 μmol/h and the O2 evolution rate of 3.1-296.2 μmol/h, depending on the composition. Stable solar hydrogen generation of up to 48 h was demonstrated by the x = 0.80 sample, with the total amount of H2 evolved over 1.6 mmol and an external quantum efficiency of 2.1%.

Flexible Substrate-Compatible and Efficiency-Improved Quantum-Dot Light-Emitting Diodes with Reduced Annealing Temperature of NiOx Hole-Injecting Layer

The growing demand for wearable and attachable displays has sparked significant interest in flexible quantum-dot light-emitting diodes (QLEDs). However, the challenges of fabricating and operating QLEDs on flexible substrates persist due to the lack of stable and low-temperature processable charge-injection/-transporting layers with aligned energy levels. In this study, we utilized NiOx nanoparticles that are compatible with flexible substrates as a hole-injection layer (HIL). To enhance the work function of the NiOx HIL, we introduced a self-assembled dipole modifier called 4-(trifluoromethyl)benzoic acid (4–CF3–BA) onto the surface of the NiOx nanoparticles. The incorporation of the dipole molecules through adsorption treatment has significantly changed the wettability and electronic characteristics of NiOx nanoparticles, resulting in the formation of NiO(OH) at the interface and a shift in vacuum level. The alteration of surface electronic states of the NiOx nanoparticles not only improves the carrier balance by reducing the hole injection barrier but also prevents exciton quenching by passivating defects in the film. Consequently, the NiOx-based red QLEDs with interfacial modification demonstrate a maximum current efficiency of 16.1 cd/A and a peak external quantum efficiency of 10.3%. This represents a nearly twofold efficiency enhancement compared to control devices. The mild fabrication requirements and low annealing temperatures suggest potential applications of dipole molecule-modified NiOx nanoparticles in flexible optoelectronic devices.

In Situ Electrochemical Cobalt Doping in Perovskite-Structured Lanthanum Nickelate Thin Film Toward Energy Conversion Enhancement of Polymer Solar Cells.

This study demonstrates that the electrochemical doping of lanthanum nickelate (LNO) with cobalt ions is a promising strategy for enhancing its physical and electrochemical properties, which are critical for energy storage and conversion devices. LNO emerges as a promising hole transport layer (HTL) in solar cells due to its stability, large band gap, and high transparency. Nevertheless, its low conductivity and improperly aligned band positions are persistent problems. Here, in a pioneering endeavor, Co-doped LNO thin films were synthesized electrochemically and applied as the HTL in polymer solar cells (PSCs). Characterization revealed the impact of Co doping on the electrochemical, structural, morphological, and optical properties of LNO thin films. Depending on the Co doping level, PSCs based on 10 mol % Co-doped LNO outperformed pure LNO, achieving a champion efficiency of 6.11% with enhanced short-circuit current density (12.84 mA cm-2), fill factor (68%), open-circuit voltage (0.70 V), and external quantum efficiency (82.6%). This enhancement resulted from decreased series resistance, refined surface morphology, minimized trap-assisted recombination, enhanced conductivity, increased charge carrier production, favorable energy level alignment, and improved current extraction facilitated by LNC0.10O HTL. Moreover, the unencapsulated PSC-LNC0.10O long-term stability notably improved and retained 86% of its initial PCE after 450 h storage in ambient air, 82% after being continuously heated to 85 °C for 300 h, and 80% after operating at maximum power point for 300 h. These findings offer a straightforward approach to enhancing PSC performance through Co doping of LNO, supported by density functional theory (DFT) calculations that validate the experimental results and confirm the improvement in optical properties and stability of PSCs as an HTL.

Efficient and stable hybrid perovskite-organic light-emitting diodes with external quantum efficiency exceeding 40 per cent

Light-emitting diodes (LEDs) based on perovskite semiconductor materials with tunable emission wavelength in visible light range as well as narrow linewidth are potential competitors among current light-emitting display technologies, but still suffer from severe instability driven by electric field. Here, we develop a stable, efficient and high-color purity hybrid LED with a tandem structure by combining the perovskite LED and the commercial organic LED technologies to accelerate the practical application of perovskites. Perovskite LED and organic LED with close photoluminescence peak are selected to maximize photon emission without photon reabsorption and to achieve the narrowed emission spectra. By designing an efficient interconnecting layer with p-type interface doping that provides good opto-electric coupling and reduces Joule heating, the resulting green emitting hybrid LED shows a narrow linewidth of around 30 nm, a peak luminance of over 176,000 cd m−2, a maximum external quantum efficiency of over 40%, and an operational half-lifetime of over 42,000 h.

High-efficiency laminated luminescent solar concentrators based on carbon dots and nanorings

Creation of novel fluorescent nanomaterials with high photoluminescence quantum yield (PLQY) will lead to high-efficiency luminescent solar concentrators (LSCs). Herein, two kinds of carbon dots (CDs), e.g., blue and green emissive CDs and one novel carbon nanorings (NRs) with yellow emission are synthesized by the solvothermal method. Diaminobenzenesulfonic acid is used as one main precursor to create blue, green emission carbon dots (B/GCDs) and yellow emission carbon nanorings (YCNRs). Importantly, the PLQYs of B/GCDs and YCNRs are 59.8±3.2 %, 12.2±0.7 % and 63.2±1.5 %, respectively. Moreover, B/GCDs and YCNRs are used as fluorescent nanomaterials to construct laminated LSCs with single-layer and double-layer through one-step photopolymerization technique. For single-layer laminated LSCs, YCNRs-based LSCs have the maximum external optical efficiency (ηopt), up to 3.05 %. Furthermore, for double-layer laminated LSCs, the LSCs based on BCDs and YCNRs achieve the highest ηopt of 4.09 %. Compared to single-layer laminated LSCs, the double-layer laminated LSCs show an increase of 34 % in ηopt. Their internal quantum efficiency (ηint) of 29.88 % and external quantum efficiency (ηext) of 25.18 % are obtained, respectively. The presented values are just for single-wavelength excitation. Thus, the synthesis of novel YCNRs with high PLQYs contributes to the optical performances at a large level. Remarkably, the optimal double-layer laminated LSCs show good transparency.

Reduced-Toxicity and Highly Luminescent Germanium-Lead Perovskites Enabled by Strain Reduction for Light-Emitting Diodes.

Germanium-lead (Ge-Pb) perovskites provide a promising solution for perovskite optoelectronic devices with reduced toxicity. However, Ge-Pb perovskite light-emitting diodes (PeLEDs) with >30 mol % Ge showed low emission efficiencies [Yang, D.; Zhang, G.; Lai, R.; Cheng, Y.; Lian, Y.; Rao, M.; Huo, D.; Lan, D.; Zhao, B.; Di, D. Germanium-Lead Perovskite Light-Emitting Diodes. Nat. Commun. 2021, 12 (1), 4295]. Here, we apply strain engineering to effectively improve the light emission efficiency and stability of Ge-Pb perovskite films and PeLEDs with 30 and 60 mol % Ge, through A-site modulation. The maximum external quantum efficiencies of the Ge-Pb PeLEDs with 30 and 60 mol % Ge are 8.5% and 3.0% at 3.32 mA cm-2 (∼922 cd m-2) and 0.53 mA cm-2 (∼60 cd m-2), respectively. Time-resolved transient absorption spectroscopy analysis of Ge-Pb perovskite films on different hole-transport layers shows that incorporating 30 mol % Ge into the perovskite with mixed A-site cations can effectively suppress trap-assisted recombination. Further analysis of their current density-voltage (J-V) curves reveals the efficiency loss mechanisms of Ge-Pb PeLEDs with high Ge fractions, indicating the possibility of further improvements.

Strategic Buried Defect Passivation of Perovskite Emitting Layers by Guanidinium Chloride for High-Performance Pure Blue Perovskite Light Emitting Diodes.

Perovskite light-emitting diodes (PeLEDs) show promise for high-definition displays due to their exceptional electroluminescent properties. However, the performance of pure blue PeLEDs is hindered by the unfavorable ionic behavior of halides and the presence of defective antisites in blue-emitting perovskite materials. An unstable buried interface between charge transport layers and the perovskite emitting layer is a major issue that limits carrier transport and recombination behavior in PeLEDs. In this study, effective buried defect passivation of pure blue perovskite emitting layers by introducing guanidinium chloride (GACl) as a bottom-passivating layer is demonstrated. The GACl bottom layer not only passivates the point defects present at the buried interface but also provides chloride anions to suppress ion migration and halide vacancy formation. Along with the defect passivation, GACl also enforces phase purity of 2D layered structure in the perovskite emitting layers to improve crystallinity and optoelectronic properties. As a result, the PeLEDs with high brightness (1200cd m-2) and excellent external quantum efficiency (6.61%) are achieved at a spectrally stable pure blue electroluminescence at 471nm (band width = 17.63nm). This study offers insights into the straightforward way for effective buried passivation for preparing high-performance PeLEDs.

Hot Exciton versus Hot Exciplex TADF Mechanism – Effect of the Donor‐Acceptor Functionalization Pattern on Anthracene‐based Emitters

Hot exciton emitters based on 9,10‐substituted anthracenes are a well‐investigated class of molecules featuring thermally activated delayed fluorescence (TADF). TADF converts triplet excitons into singlet excitons and improve the internal quantum efficiency of electroluminescent devices to performance beyond the limit of spin‐statistics of conventional emitters. In this paper, we compare different 1,8‐functionalized donor/acceptor‐substituted anthracenes and compare these to established 9,10‐functionalized hot exciton emitters. Interestingly, our new 1,8‐substituted anthracenes make use of a beneficial hot exciplex pathway, resulting in improved emission characteristics and higher photoluminescence quantum yield.

Blue‐Light‐Excitable Broadband Ca3Ga2Ge3O12:Cr3+,Ni2+ Phosphor for the Applications in NIR‐II Window

AbstractNear‐infrared (NIR) phosphor‐converted light‐emitting diode (pc‐LED) light sources in the second NIR window (NIR‐II, 1000–1700 nm) have sparked great interest for their emerging applications in non‐destructive detection and medical diagnostics fields. However, the development of efficient NIR‐II phosphors that can be excited by commercial blue LED chips remains a significant challenge, and thus impeding the applications of NIR pc‐LED. Herein, a blue‐light‐excitable broadband NIR‐II luminescence of Ni2+ is achieved upon incorporating Cr3+ and Ni2+ into the Ca3Ga2Ge3O12 (CGGO) host simultaneously. Through the energy transfer from Cr3+ to Ni2+, CGGO:Cr3+,Ni2+ phosphor presents the improved NIR‐II emission peaking at 1470 nm under 460 nm blue light excitation. The internal/external quantum efficiency values are significantly improved from 13.8%/3.3% to 24.6%/13.3% along with the enhanced luminescence thermal stability. Finally, a NIR pc‐LED is fabricated by combining CGGO:Cr3+,Ni2+ phosphor with 450 nm blue chip, and its potential applications in non‐destructive examination and biomedical imaging fields have been demonstrated. The strategy of Cr3+ and Ni2+ co‐doping solves the problem that Ni2+ luminescence cannot be effectively excited by blue light and provides the design insights to exploit more ultra‐broadband NIR pc‐LEDs based on blue LED chips.

Efficient Near-Infrared Fluorophores Based on Cyanostyrene Derivatives for Two-Photon Fluorescence Bioimaging.

Organic fluorescent materials with red/near-infrared (NIR) emission are highly promising for use in biotechnology due to their exceptional advantages. However, traditional red/NIR fluorophores often exhibit weak emission at high concentrations or in an aggregated state due to the aggregate-caused quenching effect, which severely limits their applicability in biological imaging. To address this challenge, we developed a series of cyanostyrene derivatives with aggregation-induced emission characteristics, including 2,3-Bis-(4-styryl-phenyl)-but-2-enedinitrile (DPB), 2,3-Bis-{4-[2-(4-methoxy- phenyl)-vinyl]-phenyl}-but-2-enedinitrile (DOB), 2,3-Bis-{4-[2-(4-diphenylamino- phenyl)-vinyl]-phenyl}-but-2-enedinitrile (DTB), and 2,3-Bis-[4-(2-{4-[phenyl- (4-triphenylvinyl-phenyl)-amino]-phenyl}-vinyl)- phenyl]-but-2-enedinitrile (DTTB). Notably, these compounds exhibited intense solid state fluorescence owing to AIE effect, especially DTTB shows NIR emission with high solid state quantum efficiency (712 nm, ΦF=14.2%). Then we prepared DTTB@PS-PEG NPs nanoparticles by encapsulating DTTB with the amphiphilic polymer polystyrene-polyethylene glycol (PS-PEG). Importantly, DTTB@PS-PEG NPs exhibited highly efficient NIR luminescence (ΦF=28.7%) and a large two-photon absorption cross-section (1900 GM) under 800 nm laser excitation. The bright two-photon fluorescence of DTTB@PS-PEG indicated that it can be a highly promising candidate for two-photon fluorescence probe. Therefore, this work provides valuable insights for the design of highly efficient and NIR-emitting two-photon fluorescent probes.

Purely Organic Room‐Temperature Phosphorescence Molecule for High‐Performance Non‐Doped Organic Light‐Emitting Diodes

AbstractPurely organic molecules with room‐temperature phosphorescence (RTP) are potential luminescent materials with high exciton utilization for organic light‐emitting diodes (OLEDs), but those exhibiting superb electroluminescence (EL) performances are rarely explored, mainly due to their long phosphorescence lifetimes. Herein, a robust purely organic RTP molecule, 3,6‐bis(5‐phenylindolo[3,2‐a]carbazol‐12(5H)‐yl)‐xanthen‐9‐one (3,2‐PIC‐XT), is developed. The neat film of 3,2‐PIC‐XT shows strong green RTP with a very short lifetime (2.9 μs) and a high photoluminescence quantum yield (72 %), and behaviors balanced bipolar charge transport. The RTP nature of 3,2‐PIC‐XT is validated by steady‐state and transient absorption and emission spectroscopies, and the working mechanism is deciphered by theoretical simulation. Non‐doped multilayer OLEDs using thin neat films of 3,2‐PIC‐XT furnish an outstanding external quantum efficiency (EQE) of 24.91 % with an extremely low roll‐off (1.6 %) at 1000 cd m−2. High‐performance non‐doped top‐emitting and tandem OLEDs are also achieved, providing remarkable EQEs of 24.53 % and 42.50 %, respectively. Delightfully, non‐doped simplified OLEDs employing thick neat films of 3,2‐PIC‐XT are also realized, furnishing an excellent EQE of 17.79 % and greatly enhanced operational lifetime. The temperature‐dependent and transient EL spectroscopies demonstrate the electrophosphorescence attribute of 3,2‐PIC‐XT. These non‐doped OLEDs are the best devices based on purely organic RTP materials reported so far.

Purely Organic Room-Temperature Phosphorescence Molecule for High-Performance Non-Doped Organic Light-Emitting Diodes.

Purely organic molecules with room-temperature phosphorescence (RTP) are potential luminescent materials with high exciton utilization for organic light-emitting diodes (OLEDs), but those exhibiting superb electroluminescence (EL) performances are rarely explored, mainly due to their long phosphorescence lifetimes. Herein, a robust purely organic RTP molecule, 3,6-bis(5-phenylindolo[3,2-a]carbazol-12(5H)-yl)-xanthen-9-one (3,2-PIC-XT), is developed. The neat film of 3,2-PIC-XT shows strong green RTP with a very short lifetime (2.9 μs) and a high photoluminescence quantum yield (72%), and behaviors balanced bipolar charge transport. The RTP nature of 3,2-PIC-XT is validated by steady-state and transient absorption and emission spectroscopies, and the working mechanism is deciphered by theoretical simulation. Non-doped multilayer OLEDs using thin neat films of 3,2-PIC-XT furnish an outstanding external quantum efficiency (EQE) of 24.91% with an extremely low roll-off (1.6%) at 1000 cd m‒2. High-performance non-doped top-emitting and tandem OLEDs are also achieved, providing remarkable EQEs of 24.53% and 42.50%, respectively. Delightfully, non-doped simplified OLEDs employing thick neat films of 3,2-PIC-XT are also realized, furnishing an excellent EQE of 17.79% and greatly enhanced operational lifetime. The temperature-dependent and transient EL spectroscopies demonstrate the electrophosphorescence attribute of 3,2-PIC-XT. These non-doped OLEDs are the best devices based on purely organic RTP materials reported so far.

Impacts of soil type and drought stress on growth and cesium accumulation in Napier grass.

In our previous study, the decontamination efficiency of cesium-137 (137Cs) by Napier grass (Pennisetum purpureum Schum.) in the field was shown to be variable and often influenced by natural environmental factors. To elucidate the factors influencing this variable 137Cs-decontamination efficiency, we investigated the influences of soil type and drought stress on Cs accumulation using cesium-133 (133Cs) in Napier grass grown in plastic containers. The experiment was performed using two soil types (Soil A and B) and three different soil moisture conditions: well-watered control (CL), slight drought stress (SD), and moderate drought stress (MD). Overall, our results indicate that soil type and drought have a significant impact on plant growth and 133Cs accumulation in Napier grass. Plant height (PH), tiller number (TN), leaf width (Wleaf), and dry matter weight of aboveground parts (DWabove) and root parts (DWroot) in Soil B were greater than those in Soil A. Drought stress negatively affected chlorophyll fluorescence parameters (maximal quantum efficiency of photosystem (PS) II photochemistry and potential activity of PS II), PH, TN, Wleaf, DWabove, DWroot, and total 133Cs content (TCs), but it had a positive effect on 133Cs concentration. The 133Cs concentration in the aboveground parts (Csabove) was increased by MD approximately 1.62-fold in Soil A and 1.11-fold in Soil B compared to each CL counterpart. The TCs in the aboveground parts (TCsabove) decreased due to drought by approximately 19.9%-39.0% in Soil A and 49.9%-62.7% in Soil B; however, there was no significant effect on TCsabove due to soil type. The results of this study indicate that soil moisture is a key factor in maintaining Napier grass 137Cs-decontamination efficiency.

Intramolecular exciplex featuring a bis-sp3 C-locked acceptor-donor-acceptor sandwich.

Intramolecular exciplex systems featuring thermally activated delayed fluorescence (TADF) have garnered significant attention in the realm of organic light-emitting diodes (OLEDs). Nonetheless, the occurrence of organic sandwich intramolecular exciplexes remains rare due to structural limitations and synthetic challenges. Herein, we present a novel rigid acceptor-donor-acceptor (A-D-A) sandwich complex, dSFQP, characterized by two sp3 C-locking moieties. This compound exhibits TADF characteristics facilitated by a multiple through-space charge-transfer process. X-ray crystallographic analysis confirms the distinctive sandwich configuration. The parallel spatial arrangement and minimized A-D-A configuration enhance electronic interactions, resulting in a high photoluminescence quantum yield, rapid reverse intersystem crossing rate, and sluggish nonradiative decay rate. OLEDs employing dSFQP as the dopant achieve a maximum external quantum efficiency (EQE) of 28.5% with a low efficiency roll-off of merely 2.8% at 1000 cd m-2. Even at a high brightness of 10 000 cd m-2, the EQE remains notably high at 17.5%. Our current results provide an effective way to further innovate the design of new organic charge-transfer complexes.

Synthesis and Optical Properties of CdSeTe/CdZnS/ZnS Core/Shell Nanorods.

Semiconductor nanorods (NRs) have great potential in optoelectronic devices for their unique linearly polarized luminescence which can break the external quantum efficiency limit of light-emitting diodes (LEDs) based on spherical quantum dots. Significant progress has been made for developing red, green, and blue light-emitting NRs. However, the synthesis of NRs emitting in the deep red region, which can be used for accurate red LED displays and promoting plant growth, is currently less explored. Here, we report the synthesis of deep red CdSeTe/CdZnS/ZnS dot-in-rod core/shell NRs via a seeded growth method, where the doping of Te in the CdSe core can extend the NR emission to the deep red region. The rod-shaped CdZnS shell is grown over CdSeTe seeds. By growing a ZnS passivation shell, the CdSeTe/CdZnS/ZnS NRs exhibit a photoluminescence emission peak at 670 nm, a full width at a half maximum of 61 nm and a photoluminescence quantum yield of 45%. The development of deep red NRs can greatly extend the applications of anisotropic nanocrystals.

Restraint of Nonradiative Recombination via Modulation of n-Phase Distribution through Interfacial Lithium Salt Insertion for High-Performance Pure-Blue Perovskite LEDs.

Quasi-two-dimensional perovskite has been widely used in blue perovskite light-emitting diodes. However, the performance of these devices is still hampered by random phase distribution, nonradiative recombination, and imbalanced carrier transport. In this work, an effective strategy is proposed to mitigate these limitations by inserting lithium salts at the interfaces between the hole transport layer (HTL) and the perovskite layer. The perovskite film on the inserted Li2CO3 layer exhibits reasonable n-value redistribution, which leads to the repressive nonradiation recombination and enhanced carrier transport. Moreover, the inserted Li2CO3 layer also improves the electrical conductivity of PEDOT:PSS and hinders indium ion diffusion from the PEDOT:PSS layer to the perovskite film, which inhibits exciton quenching and nonradiative recombination loss at the HTL/perovskite interface. Taking advantage of these merits, we have successfully fabricated efficient pure-blue PeLEDs with an external quantum efficiency of 6.2% at 472 nm and a luminance of 726 cd cm-2. The restraint of nonradiative recombination at the interface offers a promising approach for efficient pure-blue PeLEDs.

Efficient Energy Transfer for Near-Perfect Quantum Efficiency and Thermal Stability.

The pursuit of high-quality phosphors exhibiting swift response to near-ultraviolet (n-UV) excitation, elevated quantum efficiency (QE), superior thermal stability, and impeccable light quality has been a focal point of investigation. In this research, we synthesized a novel K2La2B2O7:Ce3+,Tb3+ (KLBO:Ce3+,Tb3+) color-tunable phosphor that meets these requirements. KLBO:Ce3+ can be stimulated efficiently by the n-UV light and shows an intense blue emission centered at 437 nm. Notably, KLBO:0.04Ce3+ exhibits exceptional internal QE (IQE = 94%) and outstanding thermal stability (I423K/I303K = 88%). Optimization of doping compositions enables efficient Ce3+ → Tb3+ energy transfer, resulting in substantial enhancements in QE and thermal stability. Specifically, KLBO:0.04Ce3+,0.28Tb3+ achieves an IQE of 98% and a thermal stability of 97%, higher than those of most phosphors of the same type. White light-emitting diodes fabricated using phosphor samples emit warm white light characterized by high Ra (Ra = 96.6 and 93.4) and low CCT (CCT = 4886 and 4400 K). This study underscores the feasibility of enhancing phosphor QE and thermal stability through energy transfer mechanisms.

Highly Stable Silver Nanowire Plasmonic Electrodes for Flexible Polymer Light-Emitting Devices.

Silver nanowire (AgNW) transparent electrodes are considered as a promising candidate for applications in flexible optoelectronic devices. However, it remains a great challenge to obtain flexible AgNW electrodes with excellent optoelectrical properties and mechanical flexibility. Here, highly stable Ag nanoparticle (AgNP)-enhanced plasmonic AgNW electrodes are demonstrated via the controllable in situ growth of AgNPs at the AgNW junctions and introduction of an l-histidine (l-His) wrapping layer. The flexible transparent electrodes of AgNW-AgNP/l-His possess a low sheet resistance (Rsh) of ∼17.5 Ω sq-1, a high transmittance of ∼92.5% (550 nm), and a robust mechanical stability (100,000 bending cycles). Benefiting from plasmon-coupling effects, flexible polymer light-emitting devices (FPLEDs) with AgNW-AgNP/l-His electrodes present a current efficiency (CE) of ∼14.8 cd A-1 and an external quantum efficiency (EQE) of ∼5.6%, constituting ∼80% and ∼75% increases compared to those of the reference devices with AgNW electrodes, respectively. Additionally, the laminated flexible transparent PLEDs (FT-PLEDs) are demonstrated by integrating polydimethylsiloxane/AgNW-AgNP anodes by a soft lamination process. The FT-PLEDs present a CE of ∼7.1 cd A-1 (cathode side: ∼3.9 cd A-1; anode side: ∼3.2 cd A-1) and an EQE of ∼2.7% (cathode side: ∼1.5%; anode side: ∼1.2%). Furthermore, the FPLEDs and FT-PLEDs exhibit robust mechanical durability, maintaining ∼89% and ∼86% of their initial luminance after 1000 bending cycles at a bending radius of 2 mm, respectively. This work opens up a new avenue for the development of high performance and stable flexible optoelectronic devices.

Angle-dependent quantum efficiency correction for improved signal accuracy in small-scale Scheimpflug lidar systems

Wide-incidence-angle detection in Scheimpflug lidar causes pixel-wise variations in signal intensity due to differences in quantum efficiency across the detector. This study proposes an angular response correction factor and a correction method to address the difference caused by a wide incidence angle. A Scheimpflug lidar system was developed with a 405 nm laser and an array image sensor; it achieved a detection angle of 11.4°. Experiments with uniform atmosphere and smoke aerosols demonstrated the effectiveness of the correction method. For uniform atmosphere, it ensured consistent signal intensity. In smoke aerosol detection, the Klett method revealed the correction factor’s role in counteracting small-scale variations in the extinction coefficient. The method improved the extinction coefficient accuracy within 4 m by 4%–75%.