Improved Electron Transport Research Articles

Hydrothermally Synthesized NiO-SnO2 Nanocomposite as an Efficient Electrocatalyst for Oxygen Evolution Reaction (OER) and Urea Oxidation Reaction (UOR)

This study presents the synthesis and electrochemical evaluation of a NiO-SnO2 nanocomposite as an advanced catalyst for the oxygen evolution reaction (OER) and urea oxidation reaction (UOR) in an alkaline medium. The NiO-SnO2 composite, prepared via hydrothermal synthesis and subsequent annealing at different temperatures (400°C, 500°C, 600°C), demonstrated excellent catalytic performance, and attributed to its unique dual-phase structure comprising monoclinic NiO and tetragonal SnO2. XRD, SEM, and XPS analyses confirmed the material's crystallinity, morphology, and chemical states, highlighting the role of annealing temperature in optimizing structural properties. Electrochemical measurements revealed that the composite annealed at 600°C exhibited superior OER and UOR activities, with overpotentials of 320mV and 140mV, respectively, at a current density of 10mAcm⁻². This enhanced performance is attributed to the synergistic effects between NiO and SnO2, which improve electron transport, active site availability, and catalyst stability. The study underscores the potential of NiO-SnO2 composites for energy-efficient water splitting and urea-rich wastewater treatment.

Electrochemical Detection and Characterization of Caffeine in Selected Tea Samples using Polyglycine Modified Carbon Paste Electrode

Glycine was electro-polymerized against a carbon paste electrode (CPE) to produce a polymer film via the electro-oxidation process comprising amino (-NH2) and carboxylic (-COOH) groups, by a cyclic voltammetric. The electrochemical oxidation of caffeine was examined in 0.2 M phosphate buffer solution (PBS). The Polyglycine modified Carbon Paste Electrode (PGMCPE) demonstrates greater electrocatalytic activity for caffeine as compared to the unmodified CPE (UNMCPE). This made it suitable for analyzing caffeine owing to its increased electrode surface area and/or improved electron transport at the electrode surface. By varying the concentration range from 0.05 to 0.9 mM, the relationship between peak current and caffeine concentration was studied and this produced a correlation coefficient of R2 = 0.9987. This method was extremely capable of evaluating caffeine concentrations. Square wave voltammetry (SWV) was utilized to assess the caffeine in tea samples. The sample was analyzed with square wave voltammetry and was made easier with an ideal pH of 12.0. Additionally, the caffeine levels in a tea sample were successfully measured using the linear range and detection limit, and the results showed a good limit of detection (LOD) in comparison to previous literature.

Tin sulfide dendritic hybrids enhanced by metallic carbon nanotubes for superior supercapacitor performance

This study presents a facile, one-step solvothermal approach to enhance the performance of SnS2-based supercapacitor electrodes through the incorporation of metallic single-walled carbon nanotubes (m-SWNTs) via a one-step solvothermal method. The resulting dendritic heterostructures exhibit significantly improved electrochemical properties compared to pristine SnS2. Comprehensive characterization using XRD, XPS, FE-SEM, and BET analysis reveals that m-SWNT incorporation leads to a significant 111.3 % increase in specific surface area and a 255.1 % increase in pore volume for the optimized SNSC5 sample. This structural modification translates to enhanced electrochemical performance, with SNSC5 demonstrating a high specific capacitance of 161 F.g−1 at 1 A.g−1, excellent cyclic stability (94.2 % retention after 5000 cycles), and a high power density of 84.7 Wkg−1. The synergistic effect of the dendritic morphology and m-SWNT network facilitates improved electron transport and ion accessibility. Furthermore, a symmetric solid-state supercapacitor device based on SNSC5 successfully powered LEDs when charged by a solar panel, showcasing its potential for practical energy storage applications. This work provides valuable insights into the design of high-performance electrode materials for next-generation supercapacitors.

Ultrafast Tailoring Amorphous Zn0.25V2O5 with Precision-Engineered Artificial Atomic-Layer 1T'-MoS2 Cathode Electrolyte Interphase for Advanced Aqueous Zinc-Ion Batteries.

Vanadium (V)-based oxides as cathode materials for aqueous zinc-ion batteries (AZIBs) still encounter challenges such as sluggish Zn2+ diffusion kinetics and V-dissolution, thus leading to severe capacity fading and limited life span. Here, we designed an ultrafast and facile colloidal chemical synthesis strategy based on crystalline Zn0.25V2O5 (c-ZVO) to successfully prepare a-ZVO@MoS2 core@shell heterostructures, where atomic-layer MoS2 uniformly coats on the surface of amorphous a-ZVO. The tailored amorphous structure of a-ZVO provides more isotropic pathways and active sites for Zn2+, thus significantly enhancing the Zn2+ diffusion kinetics during charge-discharge processes. Meanwhile, as an efficient artificial cathode electrolyte interphase, the precision-engineered atomic-layer MoS2 with semi-metallic 1T' phase not only contributes to improved electron transport but also effectively inhibits the V-dissolution of a-ZVO. Therefore, the prepared a-ZVO@MoS2 and conceptually validated a-V2O5@MoS2 derived from commercial c-V2O5 exhibit excellent cycling stability at an ultralow current density (0.05 A g-1) while maintaining good rate capability and capacity retention. This research achievement provides a new effective strategy for various amorphous cathode designs for AZIBs with superior performance.

Ultrafast Tailoring Amorphous Zn0.25V2O5 with Precision‐Engineered Artificial Atomic‐Layer 1T′‐MoS2 Cathode Electrolyte Interphase for Advanced Aqueous Zinc‐Ion Batteries

AbstractVanadium (V)‐based oxides as cathode materials for aqueous zinc‐ion batteries (AZIBs) still encounter challenges such as sluggish Zn2+ diffusion kinetics and V‐dissolution, thus leading to severe capacity fading and limited life span. Here, we designed an ultrafast and facile colloidal chemical synthesis strategy based on crystalline Zn0.25V2O5 (c‐ZVO) to successfully prepare a‐ZVO@MoS2 core@shell heterostructures, where atomic‐layer MoS2 uniformly coats on the surface of amorphous a‐ZVO. The tailored amorphous structure of a‐ZVO provides more isotropic pathways and active sites for Zn2+, thus significantly enhancing the Zn2+ diffusion kinetics during charge–discharge processes. Meanwhile, as an efficient artificial cathode electrolyte interphase, the precision‐engineered atomic‐layer MoS2 with semi‐metallic 1T′ phase not only contributes to improved electron transport but also effectively inhibits the V‐dissolution of a‐ZVO. Therefore, the prepared a‐ZVO@MoS2 and conceptually validated a‐V2O5@MoS2 derived from commercial c‐V2O5 exhibit excellent cycling stability at an ultralow current density (0.05 A g−1) while maintaining good rate capability and capacity retention. This research achievement provides a new effective strategy for various amorphous cathode designs for AZIBs with superior performance.

Fe2O3/In2O3 composite materials for dual-selective detection of H2S and NO2: Study on sensing mechanisms and sensing transition

Developing concise and efficient dual-selective gas sensors has been a significant challenge in sensing technology. In this study, a Fe2O3/In2O3 (FIO) composite material was successfully synthesized via a water bath method for highly efficient dual-selective detection of H2S and NO2. The enhanced dual-selectivity of the composite material is attributed to the high-quality heterojunction formed at the Fe2O3 and In2O3 interface, which provides more active sites and optimizes the electronic structure, thereby greatly improving electron transport efficiency. Consequently, this unique structure significantly enhances the gas sensing response and stability of the composite material. The optimal FIO-3 composite shows significant responses: 14.7 at 80 °C with 100 ppm H2S and 64.3 at 100 °C with 700 ppb NO2, achieving 7- and 31-fold improvements over pure Fe2O3. Analysis indicates that the dual-selective response of the FIO composite material is attributed to synergistic enhancement mechanisms, primarily controlled by high-temperature activation effects. Further density functional theory (DFT) studies reveal changes in charge density at the composite material interface, particularly facilitated by the formation of oxygen bridges promoting electron transfer from In2O3 to Fe2O3. This study offers new insights into the sensing transition of dual-selective gas sensors.

Polymerization of redox-active alizarin in biomass porous carbon with enhanced cycling stability for supercapacitor

Redox-active organic molecules have optimistic application prospects in energy storage due to their high theoretical capacitance, designable electrochemical activity and environmental friendliness. However, low conductivity and solubility in electrolyte severely hinder their redox activity. Here, alizarin molecules containing carbonyl and phenolic hydroxyl are encapsulated in biomass-derived porous carbon, and stable alizarin polymers are further grown on porous carbon substrate by electrochemical polymerization. Porous carbon as conductive network can improve electron transport properties, and provide suitable accommodation environment for confinement and polymerization of alizarin. The electrochemical polymerization strategy on carbon substrate allows alizarin to be connected by rigid C-O-C bond, which inhibits the dissolution of organic monomers while maintaining redox activity. The optimized polyalizarin/porous carbon composite (PAZ/PC-0.5) exhibits superior charge storage performance, with a specific capacitance of 355.8 F g−1 at 1 A g−1 and 220.8 F g−1 at high current density of 30 A g−1. Moreover, PAZ/PC electrode has more durable long-term charge-discharge stability (capacitance retention is 98 % after 10,000 charge and discharge cycles). The assembled symmetrical supercapacitor exhibits excellent energy-power characteristics (21.4 Wh kg−1 at 700 W kg−1) and durable cycle stability. This work sheds light on the design of stable organic electrode towards high-performance supercapacitor.

Synergistic coupling of NiCo-LDH in high-performance supercapacitors via hydrothermal method: Optimal utilization of the potential window

Enhancing the efficiency of layered nickel-cobalt double hydroxides (NiCo-LDH) as electrode materials represented a promising strategy for advancing supercapacitor technology and improving energy storage systems. However, achieving optimal synthesis conditions and addressing the inherent limitations of NiCo-LDH remained critical challenges. In this study, we developed a novel hydrothermal approach to fabricate ultrathin NiCo-LDH nanosheets with a highly porous architecture. In the present study, we have introduced a hydrothermal methodology aimed at the fabrication of ultrathin NiCo-LDH nanosheets characterized by an intricate and highly porous architecture. This innovative approach entailed the simultaneous deposition of nickel and cobalt hydroxides in the presence of ammonium fluoride, a technique that not only streamlined the synthesis process, but also markedly augmented the electrochemical performance of the resultant material. These effects collectively contributed to improved electron transport and structural stability. The optimized NiCo-LDH-18 electrode achieved an exceptional specific capacitance of 2266.6 F g⁻1 and an energy density of 104.8 W h kg⁻1, with a remarkable 93.19 % capacitance retention after 40,000 cycles. Additionally, the potential window of the system closely approximated its theoretical maximum, reaching 96.88 % at a current density of 10 A g⁻1. This refined synthesis strategy offered a significant advancement in supercapacitor performance and stability. By overcoming the inherent drawbacks of traditional supercapacitors, the developed materials provided an effective solution for meeting the growing demand for storage devices with high energy density.

Realizing Ultrahigh Cycle Life Anode for Sodium-Ion Batteries through Heterostructure Design and Introducing Electro Active Polymer Coating.

Bi2S3 has attracted increasing attention in sodium-ion batteries (SIBs) for its high theoretical capacity and low discharge platform. However, the sodium storage performance of Bi2S3 is limited by poor electrical conductivity and volume expansion during cycling. Herein, we report a special polypyrrole (PPy)-coated MoS2/Bi2S3 (MBS@PPy) heterostructure composite obtained by hydrothermal reaction as an anode material for SIB. As a result, the MBS@PPy composites demonstrate exceptional electrochemical performance in SIB, exhibiting a high capacity of 361.1 mA h g-1 at 10 A g-1 and showcasing remarkable rate performance. Even under a high current density of 35 A g-1, the specific capacity remains stable at 280 mA h g-1 after 2,000 cycles. Furthermore, a successfully assembled Na3V2(PO4)3//MBS@PPy sodium-ion full cell can achieve an impressive specific capacity of approximately 400 mA h g-1 after 300 cycles at 0.5 A g-1. In MBS@PPy composites, the polypyridine coating not only improves the interfacial conductivity of nanorods but also effectively inhibits the agglomeration between nanorods due to large volume changes. The MoS2 heterostructure further inhibits the coarsening of the internal structure, improves electron transport and reaction kinetics, and increases the rate capability of the material. This work provides an effective strategy to develop energy storage materials with superior electrochemical properties.

Enhancing microbial fuel cell performance for distillery wastewater treatment and bioelectricity generation: harnessing niacin as a redox mediator.

The role of redox mediators in improving electron transport from electrochemically active bacteria to the anode is crucial for enhanced bioelectricity output from microbial fuel cells (MFCs), which makes the selection of an ideal mediator very important. This study aims at exploring a new redox mediator niacin (vit B3) for enhanced bioelectricity generation in MFC while treating distillery wastewater through facile modification of anode electrode by niacin doping (MFC-NME) and simple application of niacin to the anolyte (MFC-NAA). Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) of NME confirmed the effective adsorption of niacin onto the carbon felt surface. Notably, MFC-NME exhibited a significantly higher power density (PD) of 6.36 W/m3 compared to MFC-NAA (4.59 W/m3) and control MFC (3.49W/m3). The charge transfer resistance (RCT) in MFC-NME (1.73 Ω) and MFC-NAA (2.06 Ω) were lowered by more than half than that in control MFC (4.33 Ω), which underscores the efficacy of niacin as a redox mediator. SEM analysis revealed improved bacterial attachment over the bioanode in the MFC-NME as compared to that of MFC-NAA and control MFC. Removal of chemical oxygen demand (COD) was higher in MFC-NAA (85%) and MFC-NME (80%) than in control MFC (73%) suggesting that niacin in the anolyte supported greater organic matter removal due to enriched microbial activity. Niacin used in anode modification shows great potential for improved electron transfer and enhanced bioelectricity production and supports greater wastewater treatment performance. The modified bioanode NME exhibits excellent stability.

KSCN molten salt synthesis of hierarchical MoS2/NPC for rapid and durable sodium storage

MoS2 boasts high capacity but often encounters issues such as poor electrical conductivity, limited cycling stability due to volume expansion, and polysulfide shuttling when applied as the anode in sodium-ion batteries (SIBs). To this end researchers have developed MoS2/carbon composites, which enhance electronic conductivity, ion diffusion, and structural stability. Herein, we develop a new synthesis method using a KSCN molten salt to produce hierarchical MoS2 on nitrogen and phosphorus co-doped carbon (NPC). The molten KSCN acts both as the sulfur source and the reaction medium, facilitating the creation of hierarchical MoS2 structures with a high loading of 85.8 wt%. These structures optimize ion diffusion channels and enhance electrochemical reaction kinetics. Additionally, the NPC framework improves electron transport and reduces polysulfide shuttling. With its superior structural stability and accelerated electrode kinetics, MoS2/NPC exhibits an impressive rate capacity of 468 mAh g−1 at 10 A g−1 and maintains a long lifespan of 1300 cycles at 2 A g−1. Moreover, full cells equipped with a NaNi1/3Fe1/3Mn1/3O2 cathode retain 98 % capacity retention after 400 cycles. This study presents a promising approach for fabricating advanced MoS2/carbon anodes with dedicate nanostructures for SIBs.

The Effect of Organic Semiconductor Electron Affinity on Preventing Parasitic Oxidation Reactions Limiting Performance of n-Type Organic Electrochemical Transistors.

A key challenge in the development of organic mixed ionic-electronic conducting materials (OMIEC) for high performance electrochemical transistors is their stable performance in ambient. When operating in aqueous electrolyte, potential reactions of the electrochemically injected electrons with air and water could hinder their persistence, leading to a reduction in charge transport. Here, the impact of deepening the LUMO energy level of a series of electron-transporting semiconducting polymers is evaluated, and subsequently rendering the most common oxidation processes of electron polarons thermodynamically unfavorable, on organic electrochemical transistors (OECTs) performance. Employing time resolved spectroelectrochemistry with three analogous polymers having varying electron affinities (EA), it is found that an EA below the thermodynamic threshold for oxidation of its electron polarons by oxygen significantly improves electron transport and lifetime in air. A polymer with a sufficiently large EA and subsequent thermodynamically unfavorable oxidation of electron polarons is reported, which is used as the semiconducting layer in an OECT, in its neutral and N-DMBI doped form, resulting in an excellent and air-stable OECT performance. These results show a general design methodology to avoid detrimental parasitic reactions under ambient conditions, and the benefits that arise in electrical performance.

Revealing the role of 1T- & 2H- molybdenum Disulfide/Nickel sulfide heterojunction for efficient overall water splitting

In the ongoing quest for cost-effective and durable electrocatalysts for hydrogen production—a critical element of sustainable energy transformation—the 1T phase of Molybdenum Disulfide (MoS2) faces challenges due to its thermodynamic instability and the trade-off between efficiency and durability. Conversely, the 2H phase of MoS2, often disregarded in favor of the metallic 1T phase, suffers from its inert nature and limited active sites. To overcome these limitations, this study employs a straightforward hydrothermal synthesis strategy that couples both 1T and 2H phases of MoS2 with Ni3S2, forming 1T- and 2H- MoS2/Ni3S2 heterojunctions. Enhanced by Ni3S2′s abundant active sites, improved electron transport capabilities, synergistic interface effects, and better structural stability, these heterojunctions achieve a high current density exceeding 500 mA cm−2 at low overpotentials, along with prolonged durability for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline electrolytes. Remarkably, an electrolyzer assembly utilizing 1T-MoS2/Ni3S2 as the cathode and 2H-MoS2/Ni3S2 as the anode demonstrates a competitive voltage of 1.58 V at 20 mA cm−2, showcasing superior performance in overall water splitting compared to other non-noble metal-based electrocatalysts. This study not only offers a viable method for synthesizing efficient and stable electrocatalysts for water splitting using transition metal-based heterogeneous structures but also addresses the fundamental challenges associated with 1T and 2H phases of MoS2.

Role of graphene substrate in the formation of MoS2-based nanoparticles with improved sensitivity to NO2 gas

MoS2 coatings were formed on surface-oxidized silicon, chemical vapor deposition (CVD)-grown graphene, and reduced fluorinated graphene (rFG) from ammonium tetrathiomolybdate. The samples were annealed under ultra-high vacuum conditions at a temperature of 1000 °C. Analysis of X-ray photoelectron and X-ray absorption spectra revealed a bonding between MoS2 and the supporting material that was particularly strong for CVD-graphene. Uniform covering of the flat CVD-graphene surface with MoS2 nanoparticles and numerous contacts between them promoted the removal of sulfur and the formation of exposed molybdenum edges. A cracked MoS2 coating consisting of dense domains was formed on the wrinkled rFG surface. The study of samples as NO2 gas sensors revealed the best performance of MoS2/CVD-graphene. The sensor detected NO2 in air below 50 ppb at room temperature, had good response and recovery, operated in humid air, and demonstrated excellent NO2 selectivity. The other two sensors gave signals at elevated temperatures. The advantage of MoS2/CVD-graphene is due to improved electron transport in the hybrid, accessibility of small MoS2 nanoparticles to the analyte, and passivation of high-energy molybdenum sites by oxygen, which improves NO2 desorption.

Improved electron transport in planar perovskite solar cells using TiO2, SnO2 and WO3 ultra-thin layers: a comparison on all single layer and bilayer structures

Improved electron transport in planar perovskite solar cells using TiO2, SnO2 and WO3 ultra-thin layers: a comparison on all single layer and bilayer structures

Architecting hydrogen-bonded and π–π conjugated MOF@NiPc networks towards enhanced energy storage

High-capacity metal–organic framework materials is constrained by their poor electron transport and unstable in aqueous. Herein, a spherical cobalt–nickel-based metal–organic framework (CoNi-MOF) micro-architecture with 18-π aromatic electron system of nickel phthalocyanine (NiPc) nanorods has been designed. In this system, intermolecular hydrogen (H) bonds between O in CoNi-MOF and H in nickel phthalocyanine (NiPc), along with longitudinal π-π stacking structure, could improve electron transport and structuralstability of MOFs. Benefiting from the 3D electron transport highways and “locking” effect of H bonds along with longitudinal π-π stacking structure, the optimized CoNi-MOF@NiPc electrode exhibits remarkable specific capacity of 807.365C g−1 at current density of 1 A/g, along with great cycling stability with 96.19 % capacity retention after 5000 cycles at 5 A/g, which is superior to the individual components. Besides, CoNi-MOF@NiPc//AC hybrid supercapacitor has been fabricated, which displays a maximum energy density of 130.68 Wh kg−1 at 962.09 W kg−1 and excellent cyclability (93.58 % capacity retention after 10,000 cycles). This study opens a new avenue for the design of organic electrodes and provides a new insight into H bond and π-π stacking structure effect toward advanced energy storage materials.

Synthesis and simulation study of titanium dioxide-based nanomaterial for electron carrier selective contact solar cell

This research introduces a novel approach to synthesizing titanium dioxide (TiO2) nanomaterials using the sol–gel method, specifically aimed at enhancing the performance of Silicon Heterojunction (SHJ) solar cells. The innovation lies in utilizing Iso-Propanol Alcohol and Titanium Tetra Isopropoxides for synthesis, leveraging TiO2’s wide bandgap and low work function to replace the conventional n-doped amorphous silicon layer. This approach is expected to overcome the limitations of traditional materials and significantly improve electron transport efficiency. Advanced characterization techniques were employed to assess the synthesized TiO2 nanomaterials. Atomic Force Microscopy (AFM) measured the roughness and 3D profile, while UV-V spectrophotometry evaluated the absorption properties. The structure and surface morphology were meticulously analyzed using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). These comprehensive analyses ensured a detailed understanding of the nanomaterials’ physical properties. Simulations conducted with the AFORS-HET simulator revealed that TiO2, with a refractive index compatible with a-Si:H(n) and a work function of 4.6 eV, significantly enhances SHJ solar cell performance. The results demonstrated a remarkable 22.57 % improvement in efficiency, achieving an open-circuit voltage (Voc) of 716.8 mV, a short-circuit current density (Jsc) of 37.71 mA/cm2 and a fill factor (FF) of 83.49 %. These findings underscore the potential of TiO2 nanomaterials to revolutionize SHJ solar cell technology by providing a more efficient and effective electron transport layer. Future research will focus on refining the nanostructure of TiO2 further to enhance its photovoltaic applications, aiming to push the boundaries of current solar cell efficiencies even further. This study marks a significant advancement in the field of photovoltaic materials, presenting a novel and promising solution to improving solar energy conversion.

Novel Approach of Nanophotonic Electron Transfer for Augmenting Photosynthesis in Arachis hypogaea: A Biophysical Rationale behind the Plasmonic Enhancement of Chemical Energy Transfer.

Plant photosynthetic machinery is the main source of acquisition and conversion of solar energy to chemical energy with the capacity for autonomous self-repair. However, the major limitation of the chloroplast photosystem is that it can absorb light only within the visible range of the spectrum, which is roughly 50% of the incident solar radiation. Moreover, the photosynthetic apparatus is saturated by less than 10% of available sunlight. If the capacity of solar light absorption and the transmission of resulting photons through the photosynthetic electron transport chain (ETC) can be extended, the overall efficiency of photosynthesis can be improved. The plant nanobionic approach can address this via the introduction of nanoparticles into or in the vicinity of the photosynthetic machinery/chloroplast. We have studied this exceptional nanobionic-mediated capability of two optically active nanostructures and evaluated the impact of their optical properties on plant photosynthesis. Our study revealed that metal (Ag) and core-shell metal nanostructures (AgS) can increase light absorption and improve electron transport through ETC. Both nanostructures were found to have a beneficial effect on the photoluminescence property of the isolated chloroplast. Translocation studies confirmed systemic transportation of the nanomaterial in different plant tissues. The primary growth parameters showed no detrimental effect until 21 days of treatment on Arachis hypogaea. The nano silver/silica core/shell structure (AgS) was found to be more advantageous over nano silver (AgNP) in photon entrapment, light-dependent biochemical reactions, and toxicity parameters. In the future, these nanostructures can enhance photosynthesis by increasing light absorption and resulting in higher assimilatory power generation in the form of ATP and NADPH. This approach may lead to a paradigm shift toward a sustainable method for the configuration of plant chloroplast-based hybrid energy harvesting devices.

Sequential Deposition of Diluted Aqueous SnO2 Dispersion for Perovskite Solar Cells

The widespread use of tin dioxide (SnO2) thin films as electron transport layer (ETL) of perovskite solar cells (PSCs) has been facilitated by commercial SnO2 nanocolloid dispersion. Nevertheless, challenges such as nanoparticle agglomeration have emerged, impacting film quality and interface properties critical for PSC performance. Herein, the efficacy of sequential, multistep spin‐coating of repeatedly diluted SnO2 aqueous suspension as a simple and effective approach to enhance ETL properties is explored. Through systematic experiments using dynamic light scattering, cyclic voltammetry, optical spectroscopy, and photoconductivity, it is demonstrated that the sequential deposition significantly improves the flatness and coverage of SnO2, leading to improved electron transport and transfer from a perovskite layer. Such a synergetic effect enables to fabricate lead iodide PSC (FAPbI3, FA: formamidinium) with a power conversion efficiency of 22.99% compared to 20.48% for the conventional 1‐step SnO2 layer. The findings underscore the potential of sequential SnO2 deposition as a promising technique for robust SnO2 films of photoelectric conversion devices.

Over 19% Efficient Inverted Organic Photovoltaics Featuring a Molecularly Doped Metal Oxide Electron-Transporting Layer.

Molecular doping is commonly utilized to tune the charge transport properties of organic semiconductors. However, applying this technique to electrically dope inorganic materials like metal oxide semiconductors is challenging due to the limited availability of molecules with suitable energy levels and processing characteristics. Herein, n-type doping of zinc oxide (ZnO) films is demonstrated using 1,3-dimethylimidazolium-2-carboxylate (CO2-DMI), a thermally activated organic n-type dopant. Adding CO2-DMI into the ZnO precursor solution and processing it atop a predeposited indium oxide (InOx) layer yield InOx/n-ZnO heterojunctions with increased electron field-effect mobility of 32.6 cm2 V-1 s-1 compared to 18.5 cm2 V-1 s-1 for the pristine InOx/ZnO bilayer. The improved electron transport originates from the ZnO's enhanced crystallinity, reduced hydroxyl concentrations, and fewer oxygen vacancy groups upon doping. Applying the optimally doped InOx/n-ZnO heterojunctions as the electron-transporting layers (ETLs) in organic photovoltaics (OPVs) yields cells with improved power conversion efficiency of 19.06%, up from 18.3% for devices with pristine ZnO, and 18.2% for devices featuring the undoped InOx/ZnO ETL. It is shown that the all-around improved OPV performance originates from synergistic effects associated with CO2-DMI doping of the thermally grown ZnO, highlighting its potential as an electronic dopant for ZnO and potentially other metal oxides.