- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Evaluation of epithelial transport and oxidative stress protection of nanoengineered curcumin derivative-cyclodextrin formulation for ocular delivery
摘要： Ocular drug delivery has been a well-known route for the drug administration for the treatment of ocular diseases. However, numerous anatomical and physiological barriers prevailing in the eye itself create considerable challenges for achieving the necessitated therapeutic efficacy along with ocular bioavailability. However, recent advances in nanoengineered strategies hold definite promises in terms of devising improved ophthalmic medicines for the effective drug delivery to target the sites with enhanced ocular bioavailability. Curcumin, a hydrophobic polyphenol yellow colored compound, and its metabolic reduced product, tetrahydrocurcumin (THC), have been known for their beneficial pharmacological functions, such as anti-inflammatory or anti-oxidant activities at various tissue sites. However, the low aqueous solubility of these compounds results in their poor bioavailability, thereby limiting their widespread application. Therefore, in the present study, we investigated the changes in drug solubility by forming inclusion complexes with different derivatives of hydroxypropyl (HP)-cyclodextrins (CD). To this end, the spray drying technique was used for nanoengineering curcumin or THC-loaded formulations to improve the stability of formulations during the storage. The formulations were characterized in terms of physicochemical properties and cellular permeability. The results demonstrated that the encapsulation of curcumin (or THC) into the HP-CDs significantly increased the drug solubility and enhanced the corneal and retinal epithelial permeability. Curcumin or THC complexes in HP-CDs with improved bioavailability also induced anti-oxidant activity (SOD1, CAT1, and HMOX1) in higher levels in the ocular epithelial cells and showed oxidative protection effects in rabbit cornea tissues that will boost up their application in ocular medicine.
关键词： Ophthalmic formulation,Curcumin,Retinal pigmented epithelium,Cyclodextrins,Tetrahydrocurcumin,Cellular transport,Human corneal epithelium
更新于2025-11-21 11:24:58
-
Solvent Effects on the Interface and Film Integrity of Solution-Processed ZnO Electron Transfer Layers for Quantum Dot Light Emitting Diodes
摘要： Solution-processed ZnO nanoparticle thin film is widely used as the electron transport layers (ETLs) in quantum dot light emitting diodes (QLEDs). While the ZnO nanoparticles (NPs) synthesis process has been thoroughly optimized, very few studies have focused on exploring how the solvents for dispersing the NPs affect the film-forming process, which has profound effects on the film quality and functionality as ETLs. Herein, we present a comprehensive investigation on the impact of the dispersing agent on the materials and carrier transport properties of spin-coated ZnO NP thin films. The first four members of the alkanol family, which show considerably different viscosities and volatilities, were used in this study. ZnO NP thin films deposited with different alcohols were used as the ETLs of the QLED structure and the optoelectronic performances of the devices are compared. Alcohols with high viscosity are found to cause NP agglomerations which roughen the film surface and lead to significant leakage current. Nano-cracks in the ZnO NP film are observed when a highly volatile solvent is used due to the vigorous bursts of vapor during solvent evaporation. Our results show that proper solvent can improve the surface roughness and compactness of the solution-processed ZnO films and lead to a 30% difference in the current efficiency of QLEDs. The findings here clearly indicate the important roles of the dispersing agent in the formation of high-quality NP-based thin films, which can be an important guidance for achieving high performances in QLEDs as well as a variety of solution-based devices.
关键词： Interface,Solvent,QLEDs,Electron transport layer,ZnO
更新于2025-11-21 11:01:37
-
Surface Passivation of Perovskite Solar Cells Toward Improved Efficiency and Stability
摘要： The advancement of perovskite solar cells (PVSCs) technology toward commercialized promotion needs high efficiency and optimum stability. By introducing a small molecular material such as tetratetracontane (TTC, CH3(CH2)42CH3) at the fullerene (C60)/perovskite interface of planar p-i-n PVSCs, we significantly reduced the interfacial traps, thereby suppressing electron recombination and facilitating electron extraction. Consequently, an improved efficiency of 20.05% was achieved with a high fill factor of 79.4%, which is one of the best performances for small molecular-modified PVSCs. Moreover, the hydrophobic TTC successfully protects the perovskite film from water damage. As a result, we realized a better long-term stability that maintains 87% of the initial efficiency after continuous exposure for 200 h in air.
关键词： Surface defect,Charge transport,Surface passivation,Perovskite solar cells
更新于2025-11-21 11:01:37
-
Understanding the Impact of Cu-In-Ga-S Nanoparticles Compactness on Holes Transfer of Perovskite Solar Cells
摘要： Although a compact holes-transport-layer (HTL) ?lm has always been deemed mandatory for perovskite solar cells (PSCs), the impact their compactness on the device performance has rarely been studied in detail. In this work, based on a device structure of FTO/CIGS/perovskite/PCBM/ZrAcac/Ag, that effect was systematically investigated with respect to device performance along with photo-physics characterization tools. Depending on spin-coating speed, the grain size and coverage ratio of those CIGS ?lms on FTO substrates can be tuned, and this can result in different hole transfer ef?ciencies at the anode interface. At a speed of 4000 r.p.m., the band level offset between the perovskite and CIGS modi?ed FTO was reduced to a minimum of 0.02 eV, leading to the best device performance, with conversion ef?ciency of 15.16% and open-circuit voltage of 1.04 V, along with the suppression of hysteresis. We believe that the balance of grain size and coverage ratio of CIGS interlayers can be tuned to an optimal point in the competition between carrier transport and recombination at the interface based on the proposed mechanism. This paper de?nitely deepens our understanding of the hole transfer mechanism at the interface of PSC devices, and facilitates future design of high-performance devices.
关键词： perovskite solar cells,compactness,Cu-In-Ga-S,hole transfer,holes transport layer,recombination
更新于2025-11-21 10:59:37
-
Photophysical features and semiconducting properties of propeller-shaped oligo(styryl)benzenes
摘要： Electronic, optical, and semiconducting properties of a series of propeller-shaped oligo(styryl)benzenes have been systematically investigated to monitor the effect of the number of styryl branches (three, four, and six) around a central benzene core. In order to clarify the relationships between their structures and properties, Density Functional Theory calculations were carried out at several levels of theory considering solvents with different polarity. Absorption and vibrational Raman spectroscopies showed that cruciform, four-branched derivatives present the most effective π-conjugation in agreement with the lowest calculated bond length alternation and bandgap. Deviations from the mirror image symmetry between absorption and fluorescence spectra were related to changes in the molecular conformation upon electronic excitation. Furthermore, in order to investigate the semiconducting behavior of oligo(styryl)benzenes, molecular structure changes and different electronic properties related to ionization processes were calculated and analyzed. Hole and electron reorganization energies were also computed to provide a first approximation on the n- or p-type character of these compounds. In some cases, electron reorganization energies comparable to common n-type semiconductors were found.
关键词： photophysical properties,Density Functional Theory,charge transport,Raman spectroscopy,oligo(styryl)benzenes,semiconducting properties
更新于2025-11-20 15:33:11
-
Perovskite solar cells based on polyaniline derivatives as hole transport materials
摘要： Perovskite solar cells (PSC) have been extensively studied over the past few years in both academia and industry. Despite their appeal as a low cost and ease processing PV-technology, PSC still rely on materials that are expensive, turning the large-scale production more challenging. In this work, polyaniline (PAni) and its derivative poly(o-methoxyaniline) are employed as hole transport material (HTM) in PSC, replacing the most explored HTM, spiro-OMeTAD. These very well established conducting polymers are doped with 4-dodecylbenzenesulfonic acid (DBSA) to enhance their conductivity. The correlation between the performance of the solar cells using doped and undoped conducting polymers and different metallic contacts are also evaluated. The best power conversion efficiency was 10.05% using doped PAni-DBSA with Au as contact, which is similar to the performance exhibited by our standard device using Spiro-OMeTAD as HTM.
关键词： hole transport material,perovskite solar cells,polyaniline
更新于2025-11-19 16:56:42
-
New insights into active-area-dependent performance of hybrid perovskite solar cells
摘要： The morphology of hybrid perovskite thin films depends strongly on the processing parameters due to its complex crystallization kinetics from a solution to solid perovskite halide phase. It is also profoundly sensitive to the device area of the deposited thin film, and hence reproducible photoconversion efficiency (PCE) remained a bottleneck for the fabrication of efficient photovoltaic devices having large active area. The present work focuses on the investigations of the relationship between perovskite ink concentration-dependent quality of the perovskite overlayer and PCE of the perovskite solar cells (PSC) while scaling-up process. The field-emission scanning electron microscopy images revealed that the surface coverage of perovskite overlayer depends on the concentration of perovskite solution and device area. The active-area-dependent current density (J)-voltage (V) and external quantum efficiency measurements identify morphology-dependent variation in charge-transport/recombination pathways. We confirmed that among different precursor concentrations, 40 wt% perovskite ink is suitable to produce uniform perovskite overlayer over 1 cm2. As a result, highly reproducible PCE * 13% has been achieved for the PSC having an active area of 1 cm2. Overall, our findings significantly provide new insights into the active-area-dependent PCE of PSC.
关键词： morphology,hybrid perovskite,charge-transport,photoconversion efficiency,solar cells,recombination pathways
更新于2025-11-19 16:56:42
-
2D Photonic Crystal Nanodisk Array as Electron Transport Layer for Highly Efficient Perovskite Solar Cells
摘要： Perovskite solar cells (PSCs) are currently exhibiting reproducible high efficiency; the manufacturing of low cost, scalable electron transport layers (ETLs) is becoming increasingly important. However, this remains a challenge for electron transport layers that exhibit excellent optical/electrical properties while being a thin film of simple morphology. Here we demonstrate the PSC of a 2D photonic crystal nanodisk (ND) array ETL that is compact, but greatly enhances light harvesting. The ND array is fabricated by nanosphere lithography using a monolayer of self-assembled polymer spheres as a physical mask. We fabricate ND arrays of various lattice constants simply by controlling the size of the polymer spheres. Optimal ND arrays exhibit strong forward scattering and optical confinement effects, greatly improving light harvesting in the perovskite layer. We also observe that the ND array improves charge transport by reducing contact resistance with the perovskite layer. ND array ETL PSCs reach 19% maximum power conversion efficiency, with low photocurrent-voltage hysteresis and stable photocurrent output.
关键词： optical confinement,2D photonic crystals,nanodisk array,electron transport layer,perovskite solar cells,forward scattering
更新于2025-11-19 16:46:39
-
A systematic approach to ZnO nanoparticle-assisted electron transport bilayer for high efficiency and stable perovskite solar cells
摘要： Minimizing the interface loss of perovskite solar cells is critical to achieving high photovoltaic performance, and intensive research is underway on interfacial engineering in this regard. In this work, we introduce a ZnO nanoparticles (ZnO NPs) interlayer between phenyl-C61-butyric acid methyl ester (PCBM) and a metal electrode in order to reduce the interface loss due to charge recombination and device degradation, and also investigate the dependence of device performance on the thickness and morphology of the PCBM and PCBM/ZnO electron transport bilayer. After achieving optimized PCBM and ZnO thickness, the PCBM/ZnO bilayer-based devices reached an average power conversion efficiency of 15.63% (Max. 16.39%) with an open circuit voltage of 1.05 V, short circuit current density of 18.69 mA cm-2, and fill factor of 79.95%. In addition, hysteresis behavior and atmospheric stability are significantly improved by the incorporation of a PCBM/ZnO bilayer. Therefore, the implementation of a PCBM/ZnO electron transport bilayer is a promising approach toward achieving a high-efficiency PSC with stable power output (low J-V hysteresis) and durability.
关键词： ZnO nanoparticles,interfacial engineering,stable perovskite solar cells,interface loss,high-efficiency perovskite solar cells,electron transport bilayer
更新于2025-11-19 16:46:39
-
Electrical conductivity and conduction mechanisms in (Na <sub/>0.5</sub> Bi <sub/>0.5</sub> TiO <sub/>3</sub> ) <sub/>1?x</sub> (BiScO <sub/>3</sub> ) <sub/>x</sub> (0.00 ≤ <i>x</i> ≤ 0.25) solid solutions
摘要： The electrical properties of (Na0.5Bi0.5TiO3)1-x(BiScO3)x (NBT-BS, 0.00 ≤ x ≤ 0.25) solid solutions are established by ac impedance spectroscopy and electromotive force transport number measurements. The bulk conductivity decreases with increasing BS incorporation but the oxide-ion transport number remains high (≥0.85) over a wide compositional range 0.00 ≤ x ≤ 0.15 and drops to ≈0.7 for x ≥ 0.20. NBT-BS solid solutions can only present either predominant oxide-ion conduction or mixed ionic-electronic conduction behaviour, indicating that oxide-ion conduction cannot be fully eliminated by incorporation of BS. This is in contrast from our previous study where incorporation of ≈7% BiAlO3 (BA) can fully suppress the oxide-ion conduction in NBT. The conductivity–composition relationships of NBT-BS solid solutions are attributed to a competing effect from lattice expansion, which enlarges the channel for oxygen ion migration, with trapping between B-site acceptor ions, Sc'Ti, and oxygen vacancies, V??O, which decreases oxygen ion migration. Comparisons between NBT-BS, NBT-BA and NBT-BiGaO3 (BG) solid solutions suggest that small acceptor ions on the B-site are more effective in trapping oxygen vacancies and consequently more effective to suppress the oxide-ion conduction and thus reduce dielectric loss at elevated temperatures.
关键词： transport number,electrical conductivity,solid solutions,sodium bismuth titanate,oxide-ion conduction,conduction mechanisms,impedance spectroscopy,BiScO3
更新于2025-11-14 17:28:48