Photocurrent Values Research Articles

Photocurrent in PZT/TiOx composite film prepared via self-assembly of perovskite matrix and ALD of titania

A novel approach for the preparation of ferroelectric composite films has been successfully developed by combining sol–gel evaporation-induced self-assembly (EISA) of porous lead zirconate titanate (PZT) films with atomic layer deposition (ALD) of titania. The EISA process, which utilizes a Brij-type surfactant, facilitates the formation of large columnar perovskite grains with narrow (∼20 nm) interconnected pores. ALD, employing the thermal reaction of titanium isopropoxide with water, ensures uniform titania growth within the pores throughout the film thickness, as demonstrated by transmission electron microscopy and ellipsometric porosimetry. The resulting PZT-TiOx composite films exhibit a pronounced photovoltaic current under visible light illumination, attributed to electron excitation from the valence band to Ti3+ states, followed by movement via a hopping conduction mechanism. The photocurrent value varies with the direction of polarization. This behavior presents a potential method for controlling photoconductivity through polarization, with possible applications in electronic and photonic devices.

Development of engineered Zn-MOF/g-C3N4 based photoelectrochemical system for real-time sensors and removal of naproxen in wastewater

Naproxen-contaminated water may lead to the accumulation of the drug in aquatic organisms and can pose high risks to an aquatic environment and human beings. Therefore, this work aimed to develop photoelectrochemical sensing and degradation of naproxen (NPX) using zinc-metal organic framework /graphitic carbon nitride thin film-based fluorine-doped tin oxide (Zn-MOF/g-C3N4/FTO) as anode material for the sensing and degradation of naproxen (NPX). The surface morphology, structure, surface property, surface area, optical property, photocurrent, and charge transfer kinetics abilities were studied using different techniques. The nanocomposites showed a superior photocurrent response (0.815 mA cm-2) compared to the original g-C3N4 (0.328 mA cm-2). The photo-anode made of Zn-MOF@g-C3N4/FTO displayed the highest photocurrent value, indicating that the alignment of the two semiconductor bands prevented the quick recombination of electron-hole pairs. Owing to these attractive features, the Zn-MOF/g-C3N4/FTO electrode was applied for photoelectrochemical detection of NPX using chronoamperometry. Interestingly, the nanocomposites-based FTO ascribed a lower detection limit (2.3 ng l-1) with a wide linear range concentration of NPX (0.5 to 200 µg l-1). Additionally, the analytical assessment of repeatability and reproducibility demonstrated robust performance, with commendable relative standard deviations (RSD%) of 2.54 % and 2.40 %, respectively. On the other hand, a remarkable degradation efficiency of 97.52 % was attained when employing a bias potential of 0.1 V during a 2 h photoelectrocatalytic oxidation of NPX. The degradation process was primarily driven by the active participation of holes and hydroxyl radicals in ring opening and subsequent cleavage of by-products. The notable effectiveness of this degradation can be attributed to the combined and synergistic effects of both electrochemical and photocatalytic degradation techniques. The current state demonstrates its effectiveness in the photoelectrochemical sensing and removal of NPX using MOF/g-C3N4 nanocomposites-based electrode materials in wastewater.

Creating an intermediate energy band to boost the photoelectrochemical efficiency of TiO2 for solar-driven hydrogen production

The utilization of photoelectrochemical processes for hydrogen generation from water and solar energy offers a promising avenue to replace non-renewable energy sources. Nevertheless, achieving high-performance photoanode electrodes poses a significant challenge. In this study, we present the synthesis cerium and chromium-doped TiO2 (CeCrTiO2) is produced through a simple, scalable, and cost-effective hydrothermal method on a fluorine-doped tin oxide (FTO) substrate. the introduction of Ce and Cr impurities is highlighted for its role in creating an impurity band within CeCrTiO2. This impurity band is instrumental in enhancing the separation and movement of electrons and holes, contributing to the improved performance of CeCrTiO2 as a photoanode in photoelectrochemical applications. Hence, the photocurrent density value of CeCrTiO2 is 4.5 times higher than that of bare TiO2. This suggests that CeCrTiO2 exhibits improved efficiency in generating a photocurrent when exposed to light, indicating enhanced photoelectrochemical performance. The amount of hydrogen produced by CeCrTiO2 is noted to be 4.88 times greater than that of bare TiO2. This highlights the material's effectiveness in harnessing solar energy to drive the water-splitting reaction, leading to a higher yield of hydrogen gas. The synthesis of CeCrTiO2 through a hydrothermal method results in a photoanode with significantly enhanced performance, positioning it as a promising candidate for advancing photoelectrochemical processes aimed at replacing non-renewable energy sources.

Effects of the phase transition on the photoelectrochemical properties of CuFe2O4 composite photoelectrode

In this study, CuFe2O4 was grown using various Cu:Fe source molar ratios. The morphological, structural, electrical, and photoelectrochemical properties of CuFe2O4 photoelectrodes with different structural phases based on molar ratios were analyzed. XRD and XPS were performed to systematically analyze the relationship between the structural and photoelectrochemical properties of the photoelectrode. XRD analysis revealed the phase transformation of CuFe2O4 from cubic to tetragonal phase and back to cubic phase as the Cu:Fe source molar ratio was varied. The crystallinity of Cu-rich cubic-CuFe2O4 was found to be superior to that of tetragonal-CuFe2O4. XPS analysis showed that the Cu-rich cubic-CuFe2O4 sample has higher Cu and Fe binding energies and more oxygen vacancies than the tetragonal-CuFe2O4 sample, which helps reduce carrier recombination. Additionally, cubic-CuFe2O4 samples prepared in Cu-rich conditions demonstrated high flat-band potential and low charge transfer resistance values. As a result, the cubic-CuFe2O4 photoelectrode sample under the Cu-rich condition exhibited a relatively high photocurrent density value. The highest photocurrent density value (-0.38 mA/cm2 at −0.55 VSCE) was obtained with cubic-CuFe2O4 samples prepared under the Cu:Fe 3:1 condition.

Comprehensive study on the optoelectronic properties of ZnSnP2 compound by DFT and simulation for the application in a photodetector

Abstract This article presents the density function theory (DFT) calculation of ZnSnP2 (ZTP) and its application as a photodetector. A DFT calculation has been performed to determine ZTP's optical and electronic characteristics. The direct bandgap of ZnSnP2 is found to be 1.0 eV which agrees well with the previously reported bandgap (0.95 eV). The total density of states (TDOS) of ZTP is determined to be 1.40 states/eV which is attributed to the 3p orbital of P, with minor impacts from the 3d orbital of Zn and the 5p orbital of Sn to TDOS. The real and imaginary dielectric functions and refractive indices ZTP have been determined to be 16.44 and 17.60, 4.07 and 2.92, respectively. The absorption coefficient and reflectivity of ZTP obtained from this investigation are 2.6×105 cm-1 and 57.5%, respectively. After calculating the electrionic and optical properties, ZTP-based n-CdS/p-ZnSnP2/p+-AlSb photodetector (PD) with CdS and AlSb as the window and back surface field (BSF) layers, respectively, has been computationally analyzed and optimized using solar cell capacitance simulator (SCAPS-1D). In a single heterojunction, the photocurrent, voltage, responsivity, and detectivity values have been obtained at 44.52 mA/cm2, 0.66 V, 0.73 A/W, and 6.81×1013 Jones, respectively. Insertion of a thin AlSb BSF layer improves the photocurrent, voltage, responsivity, and detectivity to 48.75 mA/cm2, 0.78 V, 0.86 A/W, and 8.22×1014 Jones, respectively. The outcomes are highly promising for the fabrication of a high performance ZTP-based PD in the future.

Low-cost fabrication methods of ZnO nanorods and their physical and photoelectrochemical properties for optoelectronic applications

Zinc Oxide (ZnO) nanorods have great potential in several applications including gas sensors, light-emitting diodes, and solar cells because of their unique properties. Here, three low cost and ecofriendly techniques were used to produce ZnO nanorods on FTO substrates: hydrothermal, chemical bath deposition (CBD), and electrochemical deposition (ECD). This study explores the impact of such methods on the optical, structural, electrical, morphological, and photoelectrochemical properties of nanorods using various measurements. XRD analysis confirmed the hexagonal wurtzite structure of ZnO nanorods in all three methods, with hydrothermal showing a preferred orientation (002) and CBD and ECD samples showing multiple growth directions, with average particle sizes of 31 nm, 34 nm, and 33 nm, respectively. Raman spectra revealed hexagonal Wurtzite structure of ZnO, with hydrothermal method exhibiting higher E2 (high) peak at 438 cm−1 than CBD and ECD methods. SEM results revealed hexagonal ZnO nanorods became more regular and thicker for the hydrothermal method, while CBD and ECD led to less uniform with voids. UV-vis spectra showed absorption lines between 390 nm and 360 nm. Optical bandgap energies were calculated as 3.32 eV, 3.22 eV, and 3.23 eV for hydrothermal, CBD, and ECD samples, respectively. PL spectra revealed UV emission band with a small intensity peak around 389 nm and visible emission peaks at 580 nm. Temperature dependent PL measurements for ZnO nanorods indicated that the intensities ratio between bound exciton and free exciton decreases with temperature increases for the three methods. Photocurrent measurements revealed ZnO nanorod films as n-type semiconductors, with photocurrent values of 2.25 µA, 0.28 µA, and 0.3 µA for hydrothermal, CBD, and ECD samples, and photosensitivity values of 8.01, 2.79, and 3.56 respectively. Our results suggest that the hydrothermal method is the most effective approach for fabricating high-quality ZnO nanorods for optoelectronic applications.

An environment-friendly phosphotungstic acid catalyzed cross-dehydrogenative coupling reaction to synthesize 9-substituted-9H-xanthenes with photoelectrochemical performance

An environment-friendly phosphotungstic acid catalyzed cross-dehydrogenative coupling reaction for the synthesis of 9-substituted-9H-xanthenes under oxygen and solvent-free conditions have been developed. The economic and practical reaction exhibited good substrate applicability tolerance, various 9-substituted-9H-xanthenes were synthesized in moderate to excellent yields by tuning the ratio of xanthenes and ketones (22 examples, up to 99% yield). By testing the photoelectrochemical performance, some of the xanthene derivatives (10c, 12c, 13c and 2d) showed stable photocurrent value, especially 2d had better cathode photocurrent value and application potential.

Theoretical prediction of chalcogen-based Janus monolayers for self-powered optoelectronic devices

Exploring potential two-dimensional monolayers with large photogalvanic effect (PGE) has been of great importance for developing self-powered optoelectronic devices. In this paper, we systematically investigate the generation of PGE photocurrent in chalcogen-based Janus XYZ monolayers (X/Y/Z = S, Se, Te; X ≠ Y ≠ Z) based on non-equilibrium Green's function formalism with density functional theory. The optimized Janus SSeTe, SeSTe, and TeSeS monolayers in the rectangular phase are shown stable and, respectively, possess 1.54, 1.49, and 1.74 eV indirect bandgaps. Illuminated by linearly polarized light, the PGE photocurrent without bias voltage can be collected in both armchair and zigzag directions. Unlike common Janus 2D materials with C3v symmetry, the photocurrent peak values of Janus XYZ monolayers do not come up with certain polarization angles, while the relations can be fitted by Iph = α sin(2θ) + β cos(2θ) + γ at each photon energy. Meanwhile, the maximum photoresponses of Janus SSeTe, SeSTe, and TeSeS monolayers are 2.02, 3.33, and 4.42 a20/photon, respectively. The relatively large PGE photocurrents and complicated polarization relations result from the lower symmetry of Janus XYZ monolayers. Moreover, the specific polarization angles for maximum photoresponses at each photon energy and the ratio between two transport directions are demonstrated, reflecting the anisotropy. Our results theoretically predict a potential Janus monolayer family for self-powered optoelectronic applications.

EFFECT OF SNO2 POROUS STRUCTURE ON ITS OPTICAL AND PHOTOELECTROCHEMICAL PROPERTIES IN WATER AND WATER-METHANOL SOLUTIONS

Tin(IV) oxide is a wide-gap semiconductor material that is widely used in photooxidation reactions of organic compounds. However, the relationship between energetic and photoelectrocatalytic properties in the oxidation of small organic molecules has not yet been sufficiently explored. In this work, a series of tin oxides were synthesized using hydrothermal, sol-gel, and template methods. Polystyrene spheres with a size of 250 nm, as well as cetyltrimethylammonium bromide, were used as templates. X-Ray diffraction, low-temperature nitrogen adsorption, X-ray photoelectron spectroscopy, Raman spectroscopy and diffuse reflectance spectroscopy methods were used to study the structure, surface composition, optical and energy characteristics. Using photoelectrochemical methods, the potentials of the conduction band and valence band were determined, and photocurrents in aqueous and aqueous-methanol solutions were studied depending on electrode polarization. It is shown that the preparation method (sol-gel or hydrothermal) does not affect the position of energy bands, while the use of a template during synthesis leads to an increase in the average pore diameter in the samples and an increase in photocurrent values in the presence of methanol. It has been established that for template-synthesized samples, the magnitude of photocurrents in a water-methanol mixture increases with an increase in the valence-band potential. The sample prepared by the hydrothermal method using a template showed the highest photocurrent values both in the background electrolyte (17.3 μA/cm2) and in the presence of methanol (26 μA/cm2), compared to the sample prepared without using a template in the electrolyte with the addition of methanol (7.6 μA/cm2) and without it (7.8 μA/cm2).

Construction of CdS/ZnO/TiO2 ternary heterojunction with hierarchical structure as photo-anode for enhancing photo-electrochemical performance

Composition and microstructure expert a significant impact on the photoelectric properties of the photo-anode. In this work, CdS/TiO2 and CdS/ZnO/TiO2 heterojunction materials were prepared using a simple and low-cost hydrothermal method. Their microstructure, crystallinity, elemental presence state and photoelectron-chemical performance of the heterojunction materials were investigated by SEM, XRD, XPS and Electrochemical workstation. The hydrothermal growth time of CdS has a significant impact on the structure and performance of heterojunctions. As the CdS deposition time increase, the photocurrent density of CdS/TiO2 shows a trend of first increasing and then decreasing. We optimized the process parameters of CdS/TiO2, and the optimal growth time for CdS is 6h. The transient photocurrent density value of CdS/TiO2 heterojunction is 0.15 mA/cm2. Depositing ZnO onto TiO2 to construct a hierarchical ZnO/TiO2 heterojunction can improve light absorption and accelerate carrier separation efficiency. The photoelectric performance of CdS/ZnO/TiO2 was compared with CdS/TiO2 and pure TiO2. The photocurrent density of CdS/ZnO/TiO2 is 1.5 mA/cm2, which is significantly larger than that of pure TiO2 and CdS/TiO2. This is due to the formation of a heterojunction between TiO2 and ZnO, which promotes the separation of carriers and ultimately improves the photoelectric performance of the CdS/ZnO/TiO2 ternary heterojunction. The fabricated CdS/ZnO/TiO2 heterojunction showed high photocurrent, which indicated a new candidate for photoelectric device.

Photoelectrochemical activity of oxide films on silver-palladium alloys in an alkaline solution

The continuously increasing energy needs of humanity are causing a number of serious environmental problems. One of the methods for the solution of such problems is the photocatalytic or photoelectrochemical production of a fairly environmentally friendly fuel - hydrogen gas. The studies in this field are mainly associated with the search for semiconductor material that is most suitable for photocatalysis. Oxides of some metals, including silver, can be used as such a material. The photocatalytic orphotoelectrochemical activity of the oxide is determined by the features of its electronic structure and can increase significantly when combined with another oxide. Therefore, anodic oxidation of binary alloys is considered as an accessible and, most importantly, controlled method for combining oxides of various metals. The aim of this study was to reveal the role of alloying of silver with palladium in the photoelectrochemical activity of oxide films anodicly formed in deaerated 0.1 M KOH. The anodic formation of oxide films was carried out by the potentiodynamic method in an alkaline medium on silver and its alloys with palladium, the concentration of which ranged from 5 to 30 at. %. Photoelectrochemical activity was assessed by the magnitude of the photocurrent generated in the oxide film directly during its formation and subsequent reduction. The photocurrent was measured in a pulsed lighting mode of the electrode surface with a quasimonochromatic LED with a wavelength of 470 nm. A positive photocurrent was recorded on all studied samples, which indicates the predominance of donor structural defects in the forming oxide film. With an increase in the concentration of palladium in the alloy, the range of potentials of photoelectrochemical activity of formed anodicly oxide films expanded. The maximum photocurrent achieved during the anodic potentiodynamic formation of the oxide film was higher, the lower the palladium concentration was. During the cathodic potentiodynamic reduction of the formed oxide films, it was possible to record even higher values of photocurrents than during their anodic formation. The highest photoelectrochemical activity, characterized by a photocurrent density of 2.89 μA/cm2 and incidental proton-to-electron conversion efficiency of 7.6%, was observed in the oxide film anodicallyformed on silver by the time the potential reached 0.6 V. Comparable values of the photocurrent and quantum efficiency (2.12 μA/cm2 and 5.6%) were recorded in the oxide film on the alloy with a palladium concentration of 10 at. % during its potentiodynamic reduction

Vanadium-doped metal-organic framework@Znln2S4 core-shell heterojunction-attenuated photoelectrochemical immunoassay

Considering that cancer has become the second leading cause of death in humans, it is essential to develop an analytical approach that can sensitively detect tumor markers for early detection. We report an attenuated photoelectrochemical (PEC) immunoassay based on the organic-inorganic heterojunction 10MIL-88B(FeV)/ZnIn2S4 (10M88B(FeV)/ZIS) as a photoactive material for monitoring carcinoembryonic antigen (CEA). The 10M88B(FeV)/ZIS heterojunctions have excellent light-harvesting properties and high electrical conductivity, which are attributed to the advantages of both organic and inorganic semiconductors, namely, remarkable photogenerated carrier separation efficiency and long photogenerated carrier lifetime. Horseradish peroxidase (HRP) in the presence of H2O2 can catalyze 3,3′-diaminofenamide (DAB) producing brown precipitates (oxDAB), which is then loaded onto the 10M88B(FeV)/ZIS heterojunction to reduce the photocurrent and enable the quantitative detection of CEA. Under optimal conditions, the photocurrent values of the PEC biosensor are linearly related to the logarithm of the CEA concentrations, ranging from 0.01 ng mL−1 to 100 ng mL−1 with a detection limit (LOD) of 4.0 pg mL−1. Notably, the accuracy of the PEC biosensor is in agreement with that of the human CEA enzyme-linked immunosorbent assay (ELISA) kit.

NiFe Prussian blue analog cocatalyzed TiO2/In2S3 type-II heterojunction for solar water splitting

Due to the excellent stability of titanium dioxide (TiO2), there is still value in improving its solar-to-hydrogen conversion efficiency through tremendous attempts. Metal sulfides with a narrow bandgap are good candidates to broaden the ultraviolet light absorption of TiO2 into the visible light region. However, sulfides suffer from the photocorrosion issue, leading to poor stability. Herein, a type-II heterojunction of TiO2/In2S3 is fabricated by a hydrothermal method, and a NiFe Prussian blue analog (NFP) overlayer is deposited on the surface of TiO2/In2S3 through a chemical bath deposition technique. Under AM1.5G illumination, a photocurrent density of 1.81 mA cm-2 can be obtained with NFP coated TiO2/In2S3 at 1.23 V vs. reversible hydrogen electrode, which is six folds of the photocurrent of TiO2. This photocurrent value can reach up to about 90% of its theoretical photocurrent. During a 12 h stability test, the TiO2/In2S3/NFP photoanode exhibits a high photocurrent retention of 95.17% after an initial transient decrease. The type-II heterojunction of TiO2/In2S3 can efficiently boost the charge separation because of the built-in electric field and enhance the visible-light absorption because of the narrow bandgap of In2S3. A NFP overlayer serves as the cocatalyst for water oxidation reaction due to its valence changes of nickel and iron elements. NFP cocatalyst can rapidly extract the photogenerated holes from In2S3 and then improve the charge separation/injection efficiencies. Thanks to chemical stability of NFP, its coating can also make In2S3 resistant to photocorrosion by physically separating the photoanode from the electrolyte. Therefore, there is a good synergistic effect between the TiO2/In2S3 heterojunction and NFP cocatalyst. This work provides some crucial insights for the interface engineering and material design in photoelectrochemical systems.

Construction of a Conductive Polymer/AuNP/Cyanobacteria-Based Biophotovoltaic Cell Harnessing Solar Energy to Generate Electricity via Photosynthesis and Its Usage as a Photoelectrochemical Pesticide Biosensor: Atrazine as a Case Study.

In this research, a cyanobacteria (Leptolyngbia sp.)-based biological photovoltaic cell (BPV) was designed. This clean energy-friendly BPV produced a photocurrent as a result of illuminating the photoanode and cathode electrodes immersed in the aqueous medium with solar energy. For this purpose, both electrodes were first coated with conductive polymers with aniline functional groups on the gold electrodes. In the cell, the photoanode was first coated with a gold-modified poly 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)benzamine polymer, P(SNS-Aniline). Thioaniline-functionalized gold nanoparticles were used to provide a cross-link formation with bis-aniline conductive bonds with the conductive polymer using electrochemical techniques. Leptolyngbia sp., one of the cyanobacteria that can convert light energy into chemical energy, was attached to this layered electrode surface. The cathode of the cell was attached to the gold electrode surface with P(SNS-Aniline). Then, the bilirubin oxidase (BOx) enzyme was immobilized on this film surface with glutaraldehyde activation. This cell, which can use light, thanks to cyanobacteria, oxidized and split water, and oxygen was obtained at the photoanode electrode. At the cathode electrode, the oxygen gas was reduced to water by the bioelectrocatalytic method. To obtain a high photocurrent from the BPV, necessary optimizations were made during the design of the system to increase electron transport and strengthen its transfer. While the photocurrent value obtained with the designed BPV in optimum conditions and in the pseudosteady state was 10 mA/m2, the maximum power value obtained was 46.5 mW/m2. In addition to storing the light energy of the system, studies have been carried out on this system as a pesticide biosensor. Atrazine biosensing via the BPV system was analytically characterized between 0.1 and 1.2 μM concentrations for atrazine, and a very low detection limit was found as 0.024 μM. In addition, response time and recovery studies related to pesticide biosensor properties of the BPV were also investigated.

Design of a Novel Green Algae‐Based Biological Photovoltaic Cell with High Photocurrent and a Photoelectrochemical Biosensing Approach Utilizing the BPV for Pesticide Analysis in Water

AbstractIn this research, a green alga (Paulschulziapseudovolvox sp.) based biological photovoltaic cell (BPV) was designed. This clean energy‐friendly BPV produced photocurrent as a result of illuminating the photoanode and cathode electrodes immersed in the aqueous medium with solar energy. For this purpose, both electrodes were first coated with conductive polymers with aniline functional groups on gold electrodes. In the cell, the photoanode was first coated with a gold‐modified poly 4‐(2,5‐di(thiophen‐2‐yl)‐1H‐pyrrol‐1‐yl)benzamine polymer, (P(SNS‐NH2)). Cytochrome C (Cyt. C) material was used to provide crosslink formation with bis‐aniline covalent bonds with the conductive polymer using electrochemical techniques. Paulschulziapseudovolvox sp., one of the green algae that can convert light energy into chemical energy, is attached to this layered electrode surface. The cathode of the cell is attached to the gold electrode surface with poly 4‐(4HDithieno[3,2‐b : 2′,3′‐d]pyrrole‐4‐yl)aniline (P(DTP‐Aryl‐Amine)). Then, the bilirubin oxidase enzyme was immobilized on this film surface with glutaraldehyde activation. This cell, which can use light thanks to green algae, oxidizes and splits water, and oxygen is obtained at the photoanode electrode. At the cathode electrode, the oxygen gas is reduced to water by the bio‐electro‐catalytic method. To obtain high photocurrent from the BPV, necessary electrochemical and chemical optimizations were made during the design of the system to increase the amount of electrons that were transferred and fasten its transfer rate. While the photocurrent value generated by the designed BPV in optimum conditions and in the pseudo‐steady state is 10 mA/m2, the maximum power value obtained is 46.5 mW/m2. In addition to the production of the green algae‐based BPV generating highly efficient electricity which is the main of target of this study, some studies have also been carried out to show whether this system can be used as a pesticide biosensor. Atrazine and diuron biosensing via the BPV system was analytically characterized and recovery and interference studies related to pesticide biosensor property of the BPV were also investigated.

Impact of Varying Position and Ratio of Charge Generation Layer on Performance Parameters of Organic Photodiode

Organic photodiodes have emerged as the best alternative to inorganic devices during the last decade. Herein, a highly efficient organic photodiode having charge generation layer (CGL) is demonstrated. This charge generation layer is a combination of HAT-CN (hexaazatriphenylene-hexacarbonitrile) and TAPC (1,1-bis[(di-4-tolyamino)phenyl)]cyclohexane) materials which generate electrons and holes, correspondingly. Moreover, in this work, the proposed device (D2) is compared with other four non-CGL (D1) and CGL based (D3, D4 and D5) devices. In all the CGL based devices, positional variation of the CGL layer is incorporated. In the proposed device (D2), the CGL is situated outside the active layer in such a manner like HAT-CN is placed near acceptor and TAPC is near donor layer. In this way, the proposed device is showing the remarkable improvements in terms of photocurrent and dark current as 134.2 nA and 10.2 nA, respectively. The value of photocurrent of D2 is 34 times increased of the reference device (D1). Furthermore, on comparing with other CGL based devices D3, D4 and D5, photocurrent of D2 is approx 1.6, 1.4 and 9 times enhanced, correspondingly. Moreover, the thickness optimization and internal analysis of the proposed device are also performed to show the novelty of the presented work.

Can electrodeposited Ti replace rolled Ti as substrate for the growth of anodic TiO2 nanotube layers?

This study conducted a deep investigation of TiO2 nanotube (TNT) layers of two different thicknesses anodically grown on electrodeposited Ti films. The Ti films were grown from molten salts on Ni foils. The structure of the starting metals was compared by XRD (X-Ray Diffraction) and EBSD (Electron Backscatter Diffraction analyses), which showed a strong orientation towards the titanium (101) for the electrodeposited substrate, compared to the rather polycrystalline structure of the rolled Ti. The photoelectrochemical and electrochemical properties of 1 μm and 5 μm thick TNT layers anodically grown on these substrates were examined and compared with TNT layers of the same thickness. No significant morphological and compositional differences were found using SEM (Scanning Electron Microscopy) and XPS (X-ray Photoelectron Spectroscopy) between the TNT layers grown on the two substrates. However, higher photocurrent densities and ICPE values were observed for TNT layers grown on electrodeposited Ti. An in-depth investigation using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) analyses showed increased conductivity of the TNT layers produced on electrodeposited Ti compared to their counterparts. The carrier density (ND) for the TNT layers on electrodeposited Ti, calculated from Mott-Schottky measurements, showed a higher doping level than the TNT layers grown on Ti foils. This increase in ND results in more optimal photoelectrochemical performance of the TNT layers grown on electrodeposited Ti. All in all, the results presented herein pave the way for the use of electrodeposited Ti, with all its inherent benefits, and allow the further study of its promising properties in a wide range of applications.

A robust methodology for PEC performance analysis of photoanodes using machine learning and analytical data.

Machine learning (ML) is increasingly applied across various fields, including chemistry, for molecular design and optimizing reaction parameters. Yet, applying ML to experimental data is challenging due to the limited number of synthesized samples, which restricts its broader application in device development. In energy harvesting, photoanodes are crucial for solar-driven water splitting, generating hydrogen and oxygen. We explored electrodes like hematite and bismuth vanadate for photocatalytic uses, noting varied photoelectrochemical performances despite similar preparations. To understand this variability, we applied a data-driven ML approach, predicting photocurrent values and identifying key performance influencers even with limited experimental data in the research development of inorganic devices. We have utilized multiple machine learning algorithms to predict the target value in the calculation process, where the contributions of the dominant descriptors were unknown. We introduced a novel methodology, incorporating clustering to manage multicollinearity from correlated analytical data and Shapley analysis for clear interpretation of contributions to performance prediction. This method was validated on hematite and bismuth vanadate, showing superior predictability and factor identification, and then extended to tungsten oxide and bismuth vanadate heterojunction photoanodes. Despite their complexity, our approach achieved determination coefficients (R2) with a prediction accuracy over 0.85, successfully pinpointing performance-determining factors, demonstrating the robustness of the new scheme in advancing photodevice research.

Preparations of MgO Nanoparticles by a Poly(acrylic acid)s Template-Assisted Method and Photovoltaic Performances of Dye-Sensitized Solar Cells based on MgO lnterlayer.

Magnesium oxide (MgO) nanoparticles are commonly used to enhance the reactivity and performance of devices and systems in various applications, primarily due to the heat-resistance, binding, and alkaline properties of MgO. However, most of the methods used to synthesize MgO nanoparticles suffer from nonuniform particle size distributions that make it difficult to manufacture stable particles. In this study, uniform magnesium oxide (MgO) nanoparticles were developed for TiO2 photoelectrodes of dye-sensitized solar cells (DSSCs) to enhance their interfacial resistances. The uniform MgO nanoparticles were synthesized from MgO 93% using a poly(acrylic acid) template-assisted method. The particle size and crystalline structure of MgO nanoparticles were characterized by NANOPHOX particle size analysis, transmission electron microscopy, and X-ray diffraction. Multilayered TiO2 photoelectrodes containing interlayers of MgO nanoparticles were fabricated as photoelectrodes for DSSC devices, and their photovoltaic performances were investigated. When the MgO interlayer was introduced into the multilayered TiO2 photoelectrode, it not only increased the photocurrent value of the DSSC device but also improved its power conversion efficiency. The DSSC device containing the MgO interlayer and the scattering layer exhibited an open-circuit voltage of 0.74 V, a short-circuit current density of 14.60 mA/cm2, and a fill factor of 0.64 under a photointensity of 100 mW/cm2 at AM 1.5, resulting in an overall solar energy conversion efficiency of 6.94%. The application of an MgO interlayer in a DSSC device exhibited improved conductivity, charge transfer ability, and excellent device performance.

Regulation of Bi2O3 phase structure improves the self-powered UV-blue dual‐band photoresponse of Bi2O3/TiO2 photodetectors and the imaging application

Bi2O3 semiconductors with excellent optical and electrical properties can be used in photodetectors (PDs). For different phase structures of Bi2O3 with corresponding optoelectronic properties in Bi2O3 due to differences in crystal structure and energy band structure, it is important to control the phase structure to obtain high-performance Bi2O3-based PDs. Herein, Bi2O3 nanosheet films with α and β phase structures controlled by the annealing temperature are deposited on the surface of TiO2 nanorod arrays (NRs) to construct ultraviolet (UV)-blue self-powered PDs. The effects of the energy band structure, Fermi level and carrier mobility of Bi2O3 films with different phase structures on the performance of Bi2O3/TiO2 PDs are investigated by combining theoretical calculations and experimental. The β-Bi2O3/TiO2 PDs with strong built-in electric field, large carrier mobility, small interfacial transfer resistance and long carrier lifetime exhibit excellent photoresponse characteristics. The PD demonstrates a responsivity of 26.7 mA W−1 and detectivity of 5.93 × 1011 Jones under 365 nm illumination. In addition, the imaging application of β-Bi2O3/TiO2 PD is explored by extending the photocurrent mapping values of a single PD unit to a complex array of optical information image processing in complex environments utilizing the UV-blue dual-band self-powered photoresponse properties of the PDs.