Prolonged Lifetime Research Articles

Facile synthesis of advanced BaTiO3/CuPbSbS3 heterostructure photocatalyst with enhanced piezo-photocatalytic degradation performance

The polarization electric field feature of piezoelectric materials is greatly beneficial to enhance the separation and migration of photogenerated carriers. Herein, we propose a BaTiO3/CuPbSbS3 (BTO/CPSS) heterostructure photocatalyst through the combination of hydrothermal and facile butyldithiocarbamate acid (BDCA) solution process, in which the catalytic degradation performance of BTO/CPSS can be effectively enhanced by the synergistic effect of piezoelectricity and semiconductor properties. Through dedicatedly adjusting the loading amount of CPSS, the Rhodamine B (RhB) degradation efficiency of BTO/CPSS achieves 9.33×10−2 min−1 along with a strong catalyst stability, which is attributed to the prolonged charge life time due to the piezoelectricity of the optimal BTO/CPSS. Moreover, the heterostructure of BTO/CPSS and polarization effect of BTO can further enhance the separation of electron-hole pairs, which can provide stronger driving force for catalytic degradation.

Highly emissive 0D Tin(II) hybrid for white LED

The pursuit of environmentally friendly and highly luminescent phosphors for down-conversion white light-emitting diodes (WLEDs) remains a significant focus of research. Here, we present a novel zero-dimensional Sn(II) hybrid exhibiting vibrant orange emission peaking at 598 nm and an outstanding photoluminescence quantum yield of 69%. This hybrid, designated as (C7H8N3)4SnBr6, was synthesized via the reaction of 2-aminobenzimidazole with SnBr2, revealing distinctive self-trapped exciton emission characteristics, contributing to its broad-band emission and prolonged lifetime. Subsequently, a down-conversion WLED was constructed by integrating the Sn(II) hybrid with a green phosphor ((Sr, Ba)2SiO4:Eu2+) and a blue phosphor (BaMgAl10O17:Eu2+), resulting in CIE coordinates of (0.313, 0.331), a correlated color temperature of 6466 K, and an impressive color rendering index of 90.6. This work enriches the family of lead-free hybrid phosphors, showcasing their potential for highly efficient white LED applications.

A comparative study of surface passivation of p-i-n perovskite solar cells by phenethylammonium iodide and 4-fluorophenethylammonium iodide for efficient and practical perovskite solar cells with long-term reliability

Passivation of the defective surface in perovskite absorber layers effectively stabilizes the photovoltaic performance and electronic properties of perovskite solar cells (PSCs). We herein investigated the passivating effects of phenethylammonium iodide (PEAI) and 4-fluorophenethylammonium iodide (F-PEAI) on perovskite absorber layers comparatively, analyzing their impact on morphological, optical, and electrical properties of perovskite absorbers. Both passivation molecules significantly improved film characteristics, with enlarged domain size, uniform surface morphologies, and prolonged carrier lifetime observed in polycrystalline perovskite absorbers. Notably, non-fluorinated PEAI demonstrated superior effectiveness in reducing tail states and defective Pb2+ sites, resulting in more stable absorbers with fewer defects. The passivated perovskite absorbers exhibited higher champion efficiencies (22.07% for PEAI and 20.56% for F-PEAI) compared to control devices (19.53%), attributed to the suppression of interfacial nonradiative recombination and reduction in recombination energy losses. The devices with passivated perovskite absorbers also demonstrated promising indoor photovoltaic performance, achieving an efficiency of 39.04% and 37.02% under dim-light conditions (LED, 6500 K, 1000 Lux), compared to 29.43% in the control device. Importantly, the passivated absorbers maintained 94% of their initial efficiency even after 1250 hours of humidity aging, indicating enhanced hydrophobicity and reduced trap states, resulting in good ambient stability. Our findings highlight the effectiveness of passivation techniques using organic ammonium halide salts in improving the efficiency and stability of perovskite solar cells.

Regulating Surface Defects to Achieve More Positive Light Soaking Effect in Perovskite Solar Cells.

The dynamic defect tolerance under light soaking is a crucial aspect of halide perovskites. However, the underlying physics of light soaking remains elusive and is subject to debate, exhibiting both positive and negative effects. In this investigation, we demonstrated that surface defects in perovskite films significantly impact the performance and stability of perovskite solar cells, closely correlated with light soaking behaviors. Removing the top surface layer through adhesive tape, the surface defect density noticeably decreases, leading to enhanced photoluminescence (PL) efficiency, prolonged carrier lifetime, and higher conductivity. Consequently, the power conversion efficiency (PCE) of solar cells improves from 17.70% to 20.5%. Furthermore, we confirmed a positive correlation between surface defects and the light soaking effect. Perovskite films with low surface defects surprisingly exhibit a 3-fold increase in PL intensity and an 85% increase in carrier lifetime under 500 s of continuous illumination at an intensity of 100 mW/cm2. Beyond the conventional strategy of suppressing defect trapping, we propose increasing the capability of dynamic defect tolerance as an effective strategy to enhance the optoelectronic properties and performance of perovskite solar cells.

Enhanced Amplified Spontaneous Emission from Perovskite Films by a Multifunctional 4′‐Aminoacetophenone Hydrochloride Additive Assistant Engineering

AbstractMetal halide perovskites are considered as a prospective candidate as optical gain media for stimulated emission, and the advancement of amplified spontaneous emission (ASE) of perovskite materials is gradually becoming the key to realize the commercialization of perovskite lasers. Nonetheless, the ASE of solution‐processed polycrystalline perovskite films still experiences a high threshold and poor optical stability due to their high defect density and poor crystalline quality. In this scenario, a noticeably ameliorated ASE performance with decreased threshold and greater photo‐stability is demonstrated in solution‐processed (FAPbI3)0.85(MAPbBr3)0.15 polycrystalline perovskite films by introducing a neoteric 4′‐Aminoacetophenone hydrochloride (APCl) additive with cost‐effective fabrication. The ASE threshold of the APCl‐embedded perovskite films is prominently curtailed from 12.8 to 5.3 µJ cm−2, with an augmented optical gain, ASE output intensity, and optical durability. The ameliorated ASE performance can be credited to multifunctional effects of the APCl additive in the perovskite films, presenting a low defect density, an unambiguously elevated photoluminescence, a prolonged decay lifetime and thus enabling the easily achieved population inversion caused by the attenuated nonradiative carrier recombination in the optical gain media. These findings provide a significant foundation and pave the way for realizing the electrically excited lasing based on the perovskite materials.

Sub-Second Long Lifetime Triplet Exciton Reservoir for Highly Efficient and Stable Organic Light-Emitting Diode.

In organic light-emitting diode (OLED), achieving high efficiency requires effective triplet exciton confinement by carrier-transporting materials, which typically have higher triplet energy (ET) than the emitter, leading to poor stability. Here, an electron-transporting material (ETM), whose ET is 0.32 eV lower than that of the emitter is reported. In devices, it surprisingly exhibits strong confinement effect and generates excellent efficiency. Additionally, the device operational lifetime is 4.9 times longer than the device with a standard ETM, 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl) phenyl (whose ET 0.36 eV is higher than the emitter). This anomalous finding is ascribed to the exceptionally long triplet state lifetime (≈0.2 s) of the ETM. It is named as long-lifetime triplet exciton reservoir effect. The systematic analysis reveals that the long triplet lifetime of ETM can compensate the requirement for high ET with the help of endothermic energy transfer. Such combination of low ET and long lifetime provides equivalent exciton confinement effect and high molecular stability simultaneously. It offers a novel molecular design paradigm for breaking the dilemma between high efficiency and prolonged operational lifetime in OLEDs.

Spontaneous crystallization of strongly confined CsSnxPb1-xI3 perovskite colloidal quantum dots at room temperature.

The scalable and low-cost room temperature (RT) synthesis for pure-iodine all-inorganic perovskite colloidal quantum dots (QDs) is a challenge due to the phase transition induced by thermal unequilibrium. Here, we introduce a direct RT strongly confined spontaneous crystallization strategy in a Cs-deficient reaction system without polar solvents for synthesizing stable pure-iodine all-inorganic tin-lead (Sn-Pb) alloyed perovskite colloidal QDs, which exhibit bright yellow luminescence. By tuning the ratio of Cs/Pb precursors, the size confinement effect and optical band gap of the resultant CsSnxPb1-xI3 perovskite QDs can be well controlled. This strongly confined RT approach is universal for wider bandgap bromine- and chlorine-based all-inorganic and iodine-based hybrid perovskite QDs. The alloyed CsSn0.09Pb0.91I3 QDs show superior yellow emission properties with prolonged carrier lifetime and significantly increased colloidal stability compared to the pristine CsPbI3 QDs, which is enabled by strong size confinement, Sn2+ passivation and enhanced formation energy. These findings provide a RT size-stabilized synthesis pathway to achieve high-performance pure-iodine all-inorganic Sn-Pb mixed perovskite colloidal QDs for optoelectronic applications.

Quasi-type-II Cu-In-Zn-S/Ni-MOF heterostructure with prolonged carrier lifetime for photocatalytic hydrogen production

Visible-driven photocatalytic hydrogen production using narrow-bandgap semiconductors has great potential for clean energy development. However, the widespread use of these semiconductors is limited due to problems such as severe charge recombination and slow surface reactions. Herein, a quasi-type-II heterostructure was constructed by combining bifunctional Ni-based metal–organic framework (Ni-MOF) nanosheets with BDC (1,4-benzenedicarboxylic acid) linker coupled with Cu-In-Zn-S quantum dots (CIZS QDs). This heterostructure exhibited a prolonged charge carrier lifetime and abundant active sites, leading to significantly improved hydrogen production rate. The optimized rate achieved by the CIZS/Ni-MOF heterostructure was 2642 μmol g−1 h−1, which is 5.28 times higher than that of the CIZS QDs. This improved performance can be attributed to the quasi-type-II band alignment between the CIZS QDs and Ni-MOF, which facilitates effective delocalization of the photogenerated electrons within the system. Additional photoelectrochemical tests confirmed the well-maintained photoluminescence and prolonged charge carrier lifetime of the CIZS/Ni-MOF heterostructure. This study provides valuable insights into the use of multifunctional MOFs in the development of highly efficient composite photocatalysts, extending beyond their role in light harvesting and charge separation.

Electron-Phonon Coupling-Mediated Ultralong Carrier Lifetime in an All-Inorganic Two-Dimensional Cs2PbI2Cl2 Perovskite: Explanation for the High Antisite Defect Tolerance.

Two-dimensional (2D) halide perovskite are appealing candidates for applications in optoelectronics and photovoltaics, but their energy conversion efficiency is severely limited by nonradiative electron-hole recombination. In most investigations, point defects with deep defect levels and deep charge-state transition levels in the band gap are treated as the carrier recombination centers. For the all-inorganic 2D Css 2PbI2Cl2, the IPb antisite defect is the most likely to form and cause nonradiative electron-hole recombination. By using density functional theory and ab initio nonradiative molecular dynamics calculations, we found that the IPb defect can introduce the deep acceptor and donor levels into the band gap. Because electron-phonon coupling gives rise to weak nonadiabatic coupling and rapid loss of electronic coherence, those levels lead to a reduction of the carrier loss and the prolongation of the excited-state carrier lifetime, thereby enhancing the photoelectric and defect tolerance properties of the Cs2PbI2Cl2 material. These results could deepen the understanding of the chemistry of defects and carrier dynamics in perovskite materials.

Highly‐Sensitive, Tri‐Modal Luminescent Manometer Utilizing Band‐Shift, Ratiometric and Lifetime‐Based Sensing Parameters

AbstractIn addressing the broad spectrum of applications for optical pressure sensors, their predominant drawback lies in their limited sensitivity to pressure fluctuations. To overcome these constraints, this study introduces a luminescent manometer harnessing the emission properties of Cr3+ ions in Li3Sc2(PO4)3, operational in three distinct reading modes: spectral shift, ratiometric, and lifetime‐based. Notably, the conducted research establishes this luminescent manometer as the most sensitive reported to date in both spectra shift (λ/dp = 23.9 nm/GPa) and lifetime‐based (SR = 93.56%/GPa) modes. A departure from conventional lifetime‐based luminescent pressure gauges, Li3Sc2(PO4)3:Cr3+ exhibits a prolongation of lifetime of the 4T2 state correlated with increasing pressure. The advantages extend beyond sensitivity, encompassing a three‐fold surge in emission intensity with pressure escalation from ambient to 3 GPa, coupled with minimal susceptibility to temperature‐induced fluctuations. Unquestionably, Li3Sc2(PO4)3:Cr3+ showcases remarkable manometric performance, validating its significant application potential in diverse scenarios within the realm of optical pressure sensors.

Simultaneously Regulated Highly Polarized and Long-Lived Valley Excitons in WSe2/GaN Heterostructures.

Interlayer excitons, with prolonged lifetimes and tunability, hold potential for advanced optoelectronics. Previous research on the interlayer excitons has been dominated by two-dimensional heterostructures. Here, we construct WSe2/GaN composite heterostructures, in which the doping concentration of GaN and the twist angle of bilayer WSe2 are employed as two ingredients for the manipulation of exciton behaviors and polarizations. The exciton energies in monolayer WSe2/GaN can be regulated continuously by the doping levels of the GaN substrate, and a remarkable increase in the valley polarizations is achieved. Especially in a heterostructure with 4°-twisted bilayer WSe2, a maximum polarization of 38.9% with a long lifetime is achieved for the interlayer exciton. Theoretical calculations reveal that the large polarization and long lifetime are attributed to the high exciton binding energy and large spin flipping energy during depolarization in bilayer WSe2/GaN. This work introduces a distinctive member of the interlayer exciton with a high degree of polarization and a long lifetime.

Large‐Scale Room‐Temperature Synthesis of the First Sb3+‐Doped Organic Ge(IV)‐Based Metal Halides with Efficient Yellow Emission for Solid‐State Lighting and Latent Fingerprint Detection

Organic–inorganic hybrid Ge(II)‐based metal halides have garnered significant interest due to their intriguing photophysical properties and environmentally friendly characteristics. However, challenges such as poor stability, low emission intensity, and a complex synthesis process have hindered their widespread application. In addressing these issues, a breakthrough in the large‐scale production of Sb3+‐doped Ge(IV)‐based metal halide (C13H14N3)2GeCl6 phosphors at room temperature through a straightforward solution method is presented. The synthesized compound exhibits a remarkable bright broad yellow emission band at 590 nm, boasting a photoluminescence quantum efficiency of 99.53 ± 0.06% the highest among Ge(IV)‐based metal halides. Notably, the introduction of Sb3+ induces the formation of Jahn–Teller‐like self‐trapped excitons in [SbCl6]3− species, attributable to lattice distortion and strong electron–phonon coupling. Consequently, Sb3+‐doped (C13H14N3)2GeCl6 demonstrates a large Stokes shift (221 nm) and a prolonged decay lifetime (3.06 μs). Furthermore, the Sb3+‐doped compound exhibits commendable chemical‐ and photostability, prompting exploration in applications such as white light‐emitting diodes and latent fingerprint detection. This work not only provides a practical approach for designing economically viable, environmentally friendly, and highly efficient emission phosphors but also paves the way for novel directions in their expanded application.

Energy-efficient deep Q-network: reinforcement learning for efficient routing protocol in wireless internet of things

<div align="center"><span>The internet of things (IoT) underscores pivotal real-world applications ranging from security systems to smart infrastructure and traffic management. However, contemporary IoT devices grapple with significant challenges pertaining to battery longevity and energy efficiency, constraining the assurance of prolonged network lifetimes and expansive sensor coverage. Many existing solutions, although promising on paper, are intricate and often impractical for real-world implementations. Addressing this gap, we introduce an energy-efficient routing protocol leveraging reinforcement learning (RL) tailored for wireless sensor networks (WSNs). This protocol harnesses RL to discern the optimal transmission route from the source to the sink node, factoring in the energy profile of each intermediary node. Training of the RL algorithm is facilitated through a reward function that includes energy outflow and data transmission efficacy. The model was compared against two prevalent routing protocols, LEACH and fuzzy C-means (FCM), for a comprehensive assessment. Simulation results highlight our protocol’s superiority with respect to the active node count, energy conservation, network longevity, and data delivery efficiency.</span></div>

Cumulative lifetime enhancement effect of deuteration in blue organic light‐emitting diodes

AbstractThis research investigates the impact of deuteration on the operational lifetime of blue organic light‐emitting diodes (OLEDs). Our study focuses on the kinetic isotope effect (KIE) and how it enhances device lifetime. Specifically, we examine the effects of deuteration on OLEDs with emitters based on common polycyclic aromatic hydrocarbons by deuterating anthracene‐based host materials. Our findings show that the deuterated analogues with incremental deuterium substitutions exhibit similar electroluminescence (EL) performances but progressively prolonged device lifetimes as a function of deuteration, indicating a cumulative enhancement effect. We observed a twofold increase in device lifetime with partial deuterium substitutions, while highly deuterated hosts realized up to a fourfold improvement. Furthermore, we found that device degradation is initiated from the interface of the hole transport layer (HTL) and emitting layer (ETL), and deuteration can mitigate the degraded reactions in the devices, thereby improving operational stability. These results provide insight into how deuteration can increase the operational lifetime of OLEDs, which has important implications for developing more efficient and durable OLED materials.

Synthesis and Photophysical Evaluation of 3,3’‐Nitrogen Bis‐Substituted fac‐[Re(CO)3(Diimine)Br] Complexes

AbstractThe preparations, photophysical and electrochemical properties of a series of fac‐[Re(CO)3(diimine)Br] complexes are presented. The bipyridine (bpy) based diimine ligands feature symmetrical and asymmetrical 3,3’‐diamino‐2,2’‐bipyridine substitution patterns. Photophysical and electrochemical properties of these complexes are tunable, depending on their organic diimine framework. Introduction of a distal urea bridge via the 3,3’‐substitution pattern led to prolonged phosphorescence lifetimes without a significant change in absorbance and phosphorescence emission wavelengths. Reversible electrochemical bipyridine reduction remained largely unchanged by this derivatization.

Selective Photoelectrochemical Oxidation of Glycerol to Glyceric Acid on (002) Facets Exposed WO3 Nanosheets

AbstractGlycerol is a byproduct of biodiesel production. Selective photoelectrochemical oxidation of glycerol to high value‐added chemicals offers an economical and sustainable approach to transform renewable feedstock as well as store green energy at the same time. In this work, we synthesized monoclinic WO3 nanosheets with exposed (002) facets, which could selectively oxidize glycerol to glyceric acid (GLYA) with a photocurrent density of 1.7 mA cm−2, a 73 % GLYA selectivity and a 39 % GLYA Faradaic efficiency at 0.9 V vs. reversible hydrogen electrode (RHE) under AM 1.5G illumination (100 mW cm−2). Compared to (200) facets exposed WO3, a combination of experiments and theoretical calculations indicates that the superior performance of selective glycerol oxidation mainly originates from the better charge separation and prolonged carrier lifetime resulted from the plenty of surface trapping states, lower energy barrier of the glycerol‐to‐GLYA reaction pathway, more abundant active sites and stronger oxidative ability of photogenerated holes on the (002) facets exposed WO3. Our findings show great potential to significantly contribute to the sustainable and environmentally friendly chemical processes via designing high performance photoelectrochemical cell via facet engineering for renewable feedstock transformation.

Multifunctional dual-anion compensation of amphoteric glycine hydrochloride enabled highly stable perovskite solar cells with prolonged carrier lifetime

Multifunctional dual-anion compensation of amphoteric glycine hydrochloride enabled highly stable perovskite solar cells with prolonged carrier lifetime

Selective Photoelectrochemical Oxidation of Glycerol to Glyceric Acid on (002) Facets Exposed WO3 Nanosheets.

Glycerol is a byproduct of biodiesel production. Selective photoelectrochemical oxidation of glycerol to high value-added chemicals offers an economical and sustainable approach to transform renewable feedstock as well as store green energy at the same time. In this work, we synthesized monoclinic WO3 nanosheets with exposed (002) facets, which could selectively oxidize glycerol to glyceric acid (GLYA) with a photocurrent density of 1.7 mA cm-2 , a 73 % GLYA selectivity and a 39 % GLYA Faradaic efficiency at 0.9 V vs. reversible hydrogen electrode (RHE) under AM 1.5G illumination (100 mW cm-2 ). Compared to (200) facets exposed WO3 , a combination of experiments and theoretical calculations indicates that the superior performance of selective glycerol oxidation mainly originates from the better charge separation and prolonged carrier lifetime resulted from the plenty of surface trapping states, lower energy barrier of the glycerol-to-GLYA reaction pathway, more abundant active sites and stronger oxidative ability of photogenerated holes on the (002) facets exposed WO3 . Our findings show great potential to significantly contribute to the sustainable and environmentally friendly chemical processes via designing high performance photoelectrochemical cell via facet engineering for renewable feedstock transformation.

Promoting Ruddlesden-Popper Perovskite Formation by Tailoring Spacer Intramolecular Interaction for Efficient and Stable Solar Cells.

Low-dimensional Ruddlesden-Popper phase (LDRP) perovskites are widely studied in the field of photovoltaics due to their tunable energy-band properties, enhanced photostability, and improved environmental stability compared to the 3D perovskites. However, the insulating spacers with weak intramolecular interaction used in LDRP materials limit the out-of-plane charge transport, leading to poor device performance of LDRP perovskite solar cells (PSCs). Here, a functional ligand, 3-guanidinopropanoic acid (GPA), which is capable of forming strong intramolecular hydrogen bonds through the carboxylic acid group, is employed as an organic spacer for LDRP PSCs. Owing to the strong interaction between GPA molecules, high-quality LDRP (GPA)2(MA)n-1PbnI3n+1 film with promoted formation of n = 5 phase, improved crystallinity, preferential vertical growth orientations, reduced trap-state density, and prolonged carrier lifetime is achieved using GPAI as the dimensionality regulator compared to butylamine hydroiodide (BAI). As a result, GPA-based LDRP PSC exhibits a champion power conversion efficiency of 18.16% that is much superior to the BA-based LDRP PSC (15.43%). Importantly, the optimized GPA-based LDRP PSCs without encapsulation show enhanced illumination, thermal, storage, and humidity stability compared to BA-based ones. This work provides new insights into producing high n value LDRP films and their efficient and stable PSCs.

Interfacial Charge Transfer Bridge Prolongs Carrier Recombination Lifetimes of CoFe Metal‐Thiolate Framework/Hematite Photoanode for Water Oxidation

AbstractConstructing heterostructural photoanodes is attractive for elevating the photoelectrochemical (PEC) performance, however, it is a long‐standing challenge to achieve highly efficient interfacial charge transfer. Herein, a CoFe metal‐thiolate framework (CoFe MTF)/Fe2O3 photoanode connected by an interfacial Fe─O─N/S bond is designed to modulate the behavior of charge carriers and improve water oxidation performance. It is disclosed that this interfacial bond functions as a direct charge transfer bridge between shallow trap states of Fe2O3 and CoFe MTF, leading to prolonged carrier recombination lifetimes (85 ns for CoFe MTF/Fe2O3 compared to 37 ns for Fe2O3) and enhanced charge transfer efficiency. Alternatively, a robust interfacial electric field is established in the CoFe MTF/Fe2O3 p–n heterojunction, facilitating efficient charge transfer. As expected, the CoFe MTF/Fe2O3 photoanode exhibits significant enhancement in water oxidation, resulting in a three‐fold increase in photocurrent density compared to pristine Fe2O3. This study highlights the significance of designing interfacially bonded heterostructural photoelectrodes to regulate the transfer characters of charge carriers.