Cation Migration-Induced Lattice Oxygen Oxidation in Spinel Oxide for Superior Oxygen Evolution Reaction.

Activating the lattice oxygen can significantly improve the kinetics of oxygen evolution reaction (OER), however, it often results in reduced stability due to the bulk structure degradation. Here, we develop a spinel FeCoCrO with active lattice oxygen by high-throughput methods, achieving high OER activity and stability, superior to the benchmark IrO. The oxide exhibits an ultralow overpotential (190 mV at 10 mA cm) with outstanding stability for over 170 h at 100 mA cm.

Critical Review of Cu-Based Hole Transport Materials for Perovskite Solar Cells: From Theoretical Insights to Experimental Validation.

Despite the remarkable efficiency of perovskite solar cells (PSCs), long-term stability remains the primary barrier to their commercialization. The prospect of enhancing stability by substituting organic transport layers with suitable inorganic compounds, particularly Cu-based inorganic hole-transport materials (HTMs), holds promise due to their high valence band maximum (VBM) aligning with perovskite characteristics. This review assesses the advantages and disadvantages of these five types of Cu-based HTMs.

High-Performance Semi-Transparent Perovskite Solar Cells with over 22% Visible Transparency: Pushing the Limit through MXene Interface Engineering.

Semi-transparent perovskite solar cells (ST-PSCs) have attracted enormous attention recently due to their potential in building-integrated photovoltaic. To obtain adequate average visible transmittance (AVT), a thin perovskite is commonly employed in ST-PSCs. While the thinner perovskite layer has higher transparency, its light absorption efficiency is reduced, and the device shows lower power conversion efficiency (PCE).

Angle-independent solar radiation capture by 3D printed lattice structures for efficient photoelectrochemical water splitting.

Photoelectrochemical water splitting is one of the sustainable routes to renewable hydrogen production. One of the challenges to deploying photoelectrochemical (PEC) based electrolyzers is the difficulty in the effective capture of solar radiation as the illumination angle changes throughout the day. Herein, we demonstrate a method for the angle-independent capture of solar irradiation by using transparent 3 dimensional (3D) lattice structures as the photoanode in PEC water splitting.

Efficient Ternary Mn-Based Spinel Oxide with Multiple Active Sites for Oxygen Evolution Reaction Discovered via High-Throughput Screening Methods.

The discovery of more efficient and stable catalysts for oxygen evolution reaction (OER) is vital in improving the efficiency of renewable energy generation devices. Given the large numbers of possible binary and ternary metal oxide OER catalysts, high-throughput methods are necessary to accelerate the rate of discovery. Herein, Mn-based spinel oxide, Fe Co Mn O, is identified for the first time using high-throughput methods demonstrating remarkable catalytic activity (overpotential of 310 mV on fluorine-doped tin oxide (FTO) substrate and 237 mV on Ni foam at 10 mA cm ).

Semitransparent Perovskite Solar Cells with > 13% Efficiency and 27% Transperancy Using Plasmonic Au Nanorods.

Semitransparent hybrid perovskites open up applications in windows and building-integrated photovoltaics. One way to achieve semitransparency is by thinning the perovskite film, which has several benefits such as cost efficiency and reduction of lead. However, this will result in a reduced light absorbance; therefore, to compromise this loss, it is possible to incorporate plasmonic metal nanostructures, which can trap incident light and locally amplify the electromagnetic field around the resonance peaks.

Solid-Ionic Memory in a van der Waals Heterostructure.

Defect states dominate the performance of low-dimensional nanoelectronics, which deteriorate the serviceability of devices in most cases. But in recent years, some intriguing functionalities are discovered by defect engineering. In this work, we demonstrate a bifunctional memory device of a MoS/BiFeO/SrTiO van der Waals heterostructure, which can be programmed and erased by solely one kind of external stimuli (light or electrical-gate pulse) via engineering of oxygen-vacancy-based solid-ionic gating.

Controllable Solution-Phase Epitaxial Growth of Q1D Sb (S,Se) /CdS Heterojunction Solar Cell with 9.2% Efficiency.

Antimony sulfoselenide (Sb (S,Se) ) is a promising photoabsorber for stable and high efficiency thin film photovoltaics (PV). The unique quasi-1D (Q1D) crystal structure gives Sb (S,Se) intriguing anisotropic optoelectronic properties, which intrinsically require the optimization of crystal growth orientation, especially for electronic devices with vertical charge transport such as solar cells. Although the efficiency of Sb (S,Se) solar cells has been improved greatly through optimizing the material quality, the fundamental issue of crystal orientation control in polycrystalline films remains unsolved, resulting in charge carrier recombination losses in the device.

An Intrinsically Micro-/Nanostructured Pollen Substrate with Tunable Optical Properties for Optoelectronic Applications.

There is broad interest in developing photonically active substrates from naturally abundant, minimally processed materials that can help to overcome the environmental challenges of synthetic plastic substrates while also gaining inspiration from biological design principles. To date, most efforts have focused on rationally engineering the micro- and nanoscale structural properties of cellulose-based materials by tuning fibril and fiber dimensions and packing along with chemical modifications, while there is largely untapped potential to design photonically active substrates from other classes of natural materials with distinct morphological features. Herein, the fabrication of a flexible pollen-derived substrate is reported, which exhibits high transparency (>92%) and high haze (>84%) on account of the micro- and nanostructure properties of constituent pollen particles that are readily obtained from nature and require minimal extraction or processing to form the paper-like substrate based on colloidal self-assembly.

The earlier the better? Nesting timing and reproductive success in subalpine cavity-nesting bees.

Reproductive timing can affect an organism's production of offspring and its offspring's success, both of which contribute to its overall fitness. In seasonal environments, the timing of reproductive activity may be restricted to short periods of the year owing to numerous potential selective pressures such as variation in daylength, weather, food availability, predation or competition. We documented the relationships between reproductive timing and individual reproductive success (total reproductive output and offspring success) in subalpine populations of five cavity-nesting solitary bee species.

Effect of Perovskite Thickness on Electroluminescence and Solar Cell Conversion Efficiency.

A hybrid organic-inorganic perovskite in a diode structure can lead to multifunctional device phenomena exhibiting both a high power conversion efficiency (PCE) of a solar cell and strong electroluminescence (EL) efficiency. Nonradiative losses in such multifunctional devices lead to an open circuit voltage () deficit, which is a limiting factor for pushing the efficiency toward the Shockley-Queisser limit. In this work, we analyze and quantify the radiative limit of in a perovskite solar cell as a function of its absorber thickness.

Surface Modification of Hematite Photoanodes with CeO Cocatalyst for Improved Photoelectrochemical Water Oxidation Kinetics.

Hematite is a promising photoanode for solar water splitting by photoelectrochemical (PEC) cells, but its performance is limited by the slow kinetics of water oxidation reaction or oxygen evolution reaction (OER). Surface modification of hematite photoanodes with a suitable water oxidation cocatalyst is a key strategy for improving the kinetics of water oxidation. In this study, a CeO overlayer is deposited on the surface of the hematite photoanode by a water-based solution method with ceric ammonium nitrate (CAN) followed by heat treatment.

Improving Carrier-Transport Properties of CZTS by Mg Incorporation with Spray Pyrolysis.

High nonradiative recombination, low diffusion length and band tailing are often associated with a large open circuit voltage deficit, which results in low efficiency of CuZnSnS (CZTS) solar cells. Recently, cation substitution in CZTS has gained interest as a plausible solution to suppress these issues. However, the common substitutes, Ag and Cd, are not ideal due to their scarcity and toxicity.

Understanding the Roles of NiO in Enhancing the Photoelectrochemical Performance of BiVO Photoanodes for Solar Water Splitting.

Solar water oxidation is considered as a promising method for efficient utilization of solar energy and bismuth vanadate (BiVO ) is a potential photoanode. Catalyst loading on BiVO is often used to tackle the limitations of charge recombination and sluggish kinetics. In this study, amorphous nickel oxide (NiO ) is loaded onto Mo-doped BiVO by photochemical metal-organic deposition method.

Doping and Switchable Photovoltaic Effect in Lead-Free Perovskites Enabled by Metal Cation Transmutation.

Creating defect tolerant lead-free halide perovskites is the major challenge for development of high-performance photovoltaics with nontoxic absorbers. Few compounds of Sn, Sb, or Bi possess ns electronic configuration similar to lead, but their poor photovoltaic performances inspire us to evaluate other factors influencing defect tolerance properties. The effect of heavy metal cation (Bi) transmutation and ionic migration on the defects and carrier properties in a 2D layered perovskite (NH ) (Sb Bi ) I system is investigated.

Synergistic Effect of Porosity and Gradient Doping in Efficient Solar Water Oxidation of Catalyst-Free Gradient Mo:BiVO.

In this paper, the synergistic effect of porosity and gradient of Mo doping in BiVO photoanodes for improving charge separation and solar water oxidation performance is reported. A simple solution-based, three-step fabrication route was adopted using a layer-by-layer assembling technique. A water oxidation photocurrent of ∼1.

Revealing the Influence of Doping and Surface Treatment on the Surface Carrier Dynamics in Hematite Nanorod Photoanodes.

Photoelectrochemical (PEC) water oxidation is considered to be the rate-limiting step of the two half-reactions in light-driven water splitting. Consequently, considerable effort has focused on improving the performance of photoanodes for water oxidation. While these efforts have met with some success, the mechanisms responsible for improvements resulting from photoanode modifications are often difficult to determine.

Impact of molybdenum out diffusion and interface quality on the performance of sputter grown CZTS based solar cells.

We have investigated the impact of CuZnSnS-Molybdenum (Mo) interface quality on the performance of sputter-grown CuZnSnS (CZTS) solar cell. Thin film CZTS was deposited by sputter deposition technique using stoichiometry quaternary CZTS target. Formation of molybdenum sulphide (MoS) interfacial layer is observed in sputter grown CZTS films after sulphurization.

Atomically Altered Hematite for Highly Efficient Perovskite Tandem Water-Splitting Devices.

Photoelectrochemical (PEC) cells are attractive for storing solar energy in chemical bonds through cleaving of water into oxygen and hydrogen. Although hematite (α-Fe O ) is a promising photoanode material owing to its chemical stability, suitable band gap, low cost, and environmental friendliness, its performance is limited by short carrier lifetimes, poor conductivity, and sluggish kinetics leading to low (solar-to-hydrogen) STH efficiency. Herein, we combine solution-based hydrothermal growth and a post-growth surface exposure through atomic layer deposition (ALD) to show a dramatic enhancement of the efficiency for water photolysis.

Understanding charge transport in non-doped pristine and surface passivated hematite (FeO) nanorods under front and backside illumination in the context of light induced water splitting.

Hematite (FeO) nanorods on FTO substrates have been proven to be promising photoanodes for solar fuel production but only with high temperature thermal activation which allows diffusion of tin (Sn) ions from FTO, eventually enhancing their conductivity. Hence, there is a trade-off between the conductivity of FeO, and the degradation of FTO occurring at high annealing temperatures (>750 °C). Here, we present a comprehensive study on undoped FeO nanorods under front and back illumination to find the optimum annealing temperature.

Improved Charge Separation in WO₃/CuWO₄ Composite Photoanodes for Photoelectrochemical Water Oxidation.

Porous tungsten oxide/copper tungstate (WO₃/CuWO₄) composite thin films were fabricated via a facile conversion method, with a polymer templating strategy. Copper nitrate (Cu(NO₃)₂) solution with the copolymer surfactant PluronicF-127 (Sigma-Aldrich, St. Louis, MO, USA, generic name, poloxamer 407) was loaded onto WO₃ substrates by programmed dip coating, followed by heat treatment in air at 550 °C.

Wire-shaped perovskite solar cell based on TiO2 nanotubes.

In this work, a wire-shaped perovskite solar cell based on TiO2 nanotube (TNT) arrays is demonstrated for the first time by integrating a perovskite absorber on TNT-coated Ti wire. Anodization was adopted for the conformal growth of TNTs on Ti wire, together with the simultaneous formation of a compact TiO2 layer. A sequential step dipping process is employed to produce a uniform and compact perovskite layer on top of TNTs with conformal coverage as the efficient light absorber.

Chemical Bath Deposition of p-Type Transparent, Highly Conducting (CuS)x:(ZnS)1-x Nanocomposite Thin Films and Fabrication of Si Heterojunction Solar Cells.

P-type transparent conducting films of nanocrystalline (CuS)x:(ZnS)1-x were synthesized by facile and low-cost chemical bath deposition. Wide angle X-ray scattering (WAXS) and high resolution transmission electron microscopy (HRTEM) were used to evaluate the nanocomposite structure, which consists of sub-5 nm crystallites of sphalerite ZnS and covellite CuS. Film transparency can be controlled by tuning the size of the nanocrystallites, which is achieved by adjusting the concentration of the complexing agent during growth; optimal films have optical transmission above 70% in the visible range of the spectrum.

Influence of void-free perovskite capping layer on the charge recombination process in high performance CH3NH3PbI3 perovskite solar cells.

The stunning rise of methylammonium lead iodide perovskite material as a light harvesting material in recent years has drawn much attention in the photovoltaic community. Here, we investigated in detail the uniform and void-free perovskite capping layer in the mesoscopic perovskite devices and found it to play a critical role in determining device performance and charge recombination process. Compared to the rough surface with voids of the perovskite layer, surface of the perovskite capping layer obtained from sequential deposition process is much more uniform with less void formation and distribution within the TiO2 mesoscopic scaffold is more homogeneous, leading to much improved photovoltaic parameters of the devices.

Carbon nanotubes as an efficient hole collector for high voltage methylammonium lead bromide perovskite solar cells.

A high open circuit voltage (V(OC)) close to 1.4 V under AM 1.5, 100 mW cm(-2) conditions is achieved when carbon nanotubes (CNTs) are used as a hole conductor in methyl ammonium lead bromide (MAPbBr3) perovskite solar cells.