Advanced Energy Materials

Half-Heusler n-type thermoelectric materials MNiSn (M = Hf, Zr) exhibit peak thermoelectric figure-of-merit (ZT) of ∼1.0 at 600–700 °C with a composition of Hf_0.75Zr_0.25NiSn_0.99Sb_0.01. This work achieves the same ZT by reducing the concentration of the most expensive component Hf to one third of the previously reported best composition, i.e., Hf_0.25Zr_0.75NiSn_0.99Sb_0.01, which corresponds to an overall 50% reduction on material cost.

Stepwise construction of functional triazatruxene platforms allow linking to preorganized diketopyrrolopyrrole bearing thienyl subunits. These dyes exhibit strong absorption until 750 nm in thin films and show favorable redox activity allowing producing efficient organic solar cells when blended in solution with PC₇₁BM. A maximum power conversion efficiency of 5.3% was obtained.

An advanced heterojunction structure is introduced for polymer photovoltaic cells that can approach almost 100% internal quantum efficiency (IQE) even with over 300 nm thick electron-donor layer for adequate light absorption. These devices show superior charge transport property as well as non-Langevin type bimolecular recombination. The resultant short circuit current of the device is about 50% higher than that of the thermally annealed BHJ polymer PV cell.

The oxidation stabilities of nanographite materials (NGMs) including single/double-walled carbon nanotubes and graphene are investigated. The key factors which influence the oxidation behavior of NGMs such as double layer capacitance, electrical conductivity and specific surface area is clarified. A facile and effective solution to increase resistance to oxidation is developed.

Leaf-like V₂O₅ nanosheets are fabricated by a facile green approach. Used as cathode material for lithium-ion batteries, this nano-structured material exhibits superior performance, i.e., high rate capability and good capacity retention upon cycling. Thus, the leaf-like V₂O₅ Nanosheets are promising as a cathode material for high power lithium batteries.

A new approach for in situ electron microscopy of single Li-ion battery cathode particles reveals significant separations between grains (primary particles) and electrolyte penetration to the interior of cathode particles occuring even during the very first charge cycle. These results elucidate several aspects of battery performance and suggest additional mechanisms for degradation of battery performance and capacity.

A steady-state method to probe bimolecular recombination in organic solar cells is presented. The technique is applicable to thin-film solar cells at any temperature and does not require a separate measurement setup other than conventional solar-cell testing equipment. The key element in our method is the derivation of a simple analytical expression that directly gives access to the recombination strength.

A novel LiFePO₄ cathode material (LFP@C/CNT) whereby the LiFePO₄ nanoparticles are decorated with both an amorphous carbon coating and conducting carbon nanotubes is shown. This material exhibits much improved electrochemical properties in terms of specific capacity, rate capability, cycling, and low-temperature performances benefiting from the enhanced electronic and ionic conductivities, stabilized interface and lower charge polarization compared to pristine LFP and other carbon-decorated LFP materials.

The sodium storage properties of layered Na₂Ti₃O₇, as a potential anode material for sodium-ion batteries, are elaborated from thermodynamic and kinetic aspects. An interesting zero-current overpotential related to thermodynamic factors in Na₂Ti₃O₇ is studied. The electronic structure and sodium transport properties are experimentally investigated, combined with first-principles calculations.

A dense, conformal, thin-film coating of Pr_0.75Sr_0.2MnO_3−δ (PSM) and PrSrCoMnO_6–δ (PSCM) on a state-of-the-art La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ (LSCF)-based cathode for solid oxide fuel cells (SOFC) has drastically enhanced the electro-catalytic activity and stability of the cathode, suggesting that they are excellent electro-catalysts for surface modification of SOFC cathodes. The catalyst coating is introduced by a low-cost, one-step solution infiltration process.

A good combination: Based on the previous best binary compositions, thermoelectric figures-of-merit (ZT) of 0.97 at 700 °C and ≥1 at 800 °C were achieved in Hf_0.44Zr_0.44Ti_0.12CoSb_0.8Sn_0.2. This composition has two advantages over the previous two best compositions: higher ZT than Hf_0.5Zr_0.5CoSb_0.8Sn_0.2 and less of the most expensive component, Hf, than in Hf_0.8Ti_0.2CoSb_0.8Sn_0.2.

A linear solution-processable small molecule (BDT-2DPP) based on 5-alkylthiophene-2-yl-substituted benzodithiophene and diketopyrrolopyrrole is designed and synthesized. BDT-2DPP exhibits strong and broad absorption with low band gap, low lying energy levels matching with PC₆₁BM and high hole mobility. Solution-processed organic solar cells based on BDT-2DPP:PC₆₁BM blend showed power conversion efficiencies as high as 5.79%.

Screen printing of graphene based ink shows promise for the integration of graphene within supercapacitor electrodes. A series of graphene/polyaniline inks are formulated, and screen printing is used to produce thin-film electrodes from these inks. Using these electrodes, supercapacitors are fabricated which exhibit high capacity, flexibility, and stability. These results provide an important step towards the industrial development of printable supercapacitors.

A novel in situ approach is developed to probe the electronic structure across the interface of nanoscale multilayer systems at high temperature and in oxygen environment. Using this approach, the (La_0.5Sr_0.5)₂CoO₄/La_0.8Sr_0.2CoO₃ (LSC_214/113) multilayer is investigated, and the electronic activation of LSC₂₁₄ at high temperature by LSC₁₁₃ is discovered, which leads to the ultra-high oxygen reduction activity near the LSC_113/214 interface.

A nanoporous polytetrafluoroethylene (PTFE)/silica composite separator has been successfully developed for all-vanadium redox flow battery (VRB). The new separator has demonstrated an excellent combination of chemical stability, conductivity, capacity retention, and cost for VRB application, offering great promise as a substitute for the Nafion membrane.

Enhanced efficiency parameters of solution-processable small-molecule bulk-heterojunction solar cells are successfully achieved using ITO substrate with a sheet resistance of 5 Ω/□. The PCE of the device with a 5 Ω/□-ITO shows 8.24% with enhanced J_SC of 14.74 mA/cm², and fill factor of 72.4%. Furthermore, the PCE and FF values are optimized and reproducible due to an improved shunt resistance and a reduced series resistance of the small molecule solar cells.

Both the acoustic phonon scattering and alloy scattering contribute to the carrier transport in the Sb doped Mg₂Si_0.45Sn_0.55 solid solutions. A low deformation potential and a low alloy scattering potential have been derived by modeling of thermoelectric transport properties, which are believed to be intrinsic features contributing to the high thermoelectric performance of the solid solutions.

Carbon nanotube–silicon solar cells have recently been reported with 15% conversion efficiency; however, the mechanism of action of such devices is still uncertain. In this paper, the role of the nanotubes in the carbon nanotube-silicon design is examined, using nanotube material highly enriched in small or large diameter semiconducting nanotubes, yielding unexpected results.

Transparent luminescent solar concentrators are a new standard for selective light harvesting allowing for non-tinted, transparent, and highly scalable solar windows. These devices are enabled by exploiting phosphorescent hexanuclear nanocrystalline-polymer blends that exhibit massive Stokes-shifts, high phosphorescent quantum yield, high stability, and perfectly tuned absorption/emission around the visible spectrum.

Inkjet printing can be used to manufacture flexible organic radical battery (ORB) electrodes. A reactive printing approach based on the thermal crosslinking of amine bearing redoxactive radical polymers was developed. The printed electrodes are stable for over one hundred charging/discharging cycles.

Graphene quantum dots (GQDs) are explored as a green sensitizer to functionalize ZnO nanowire arrays (GQDs@ZnO NWs) by covalently bonding GQDs on ZnO NWs that have been grown on F-doped SnO₂ glass and modified with amine groups. Using a Pt counter electrode, the GQDs@ZnO NWs photoelectrodes exhibit enhanced performance for photoelectrochemical water splitting.

A novel chemically stable proton conductor BaZr_0.7Sn_0.1Y_0.2O_3–δ (BZSY) with sufficiently high conductivity is developed for solid oxide fuel cells (SOFCs). The single cell with a 12-μm-thick BZSY electrolyte film outputs by far the best performance for BaZrO₃-based proton-conducting SOFCs, achieving 360 mW cm⁻² at 700 °C. The result is a significant progress for proton-conducting SOFCs, demonstrating that BZSY is a promising electrolyte material for low-temperature SOFCs.

This article reports an unexpected behavior of graphene in graphene–silicon heterojunction junction solar cells when it is used as the window electrode. Although the synthesized monolayer graphene exhibited better transparency and conductivity, the multilayer graphene enabled much higher solar conversion ability of the solar cell. This surprising observation may be because the multilayer graphene can more effectively suppress charge recombination at the heterojunction interface, which increases the fill factor and enhances the cell performance.

The electronic conductivity of lithium titanate spinel (Li_4/3Ti_5/3O₄) is measured as a function of lithiation and temperature. The electronic conductivity of fully lithiated spinel (Li_7/3Ti_5/3O₄) is 2.46 S/cm at 300 K and is weakly thermally activated. High electronic conductivity is observed over a wide lithiation range down to x~0.04 and suggests that lithium chemical diffusion is ionically limited over most of the state of charge regime.

An alcohol-soluble imidazolium-substituted polythiophene is fabricated to enhance the photovoltaic performance of polymer solar cells. The conjugated polyelectrolyte is used as an additional electron transport layer, boosting the inherent I–V characteristics of the resulting devices. The ionic polythiophene interlayer is compared with known electron transport materials and shows improved power conversion efficiencies.

The correlated electron “metal” SrRuO₃ exhibits strong visible slight absorption. Overlaid on the AM1.5G solar spectrum, it can be seen that SrRuO₃ absorbs more than 75 times more light than TiO₂. The structural, chemical, and electronic compatibility of TiO₂ and SrRuO₃ further enables the fabrication of heterojunctions with exciting photovoltaic and photocatalytic response driven by hot-carrier injection.

Ultrathin MoS₂/N-graphene nanosheets with ∼4 nm thickness exhibit exceptional electrochemical performance. Extension of the defect sites and vacancies of the nanosheets results in the increase of capacity during cycling.

Aromatic polythiourea is a dielectric polymer with low high-field loss and excellent electrical breakdown strength (>1.1 GV/m,). The dielectric constant of 4.5 and high breakdown strength lead to a high maximum energy density of >24 J/cc in the material. The conduction mechanisms and structure–property relationships which lead to these properties are the focus of this work.

The use of earth-abundant and green calcium and sulfur is reported in unprecedented conversion reaction Ca–S primary cells. Discharge capacities as high as 600 mAh g⁻¹ (S basis) within the geometry Ca|Ca(ClO₄)₂/CH₃CN|S/C composite, are achieved at a discharge rate of C/3.5. The electrolyte system in the Ca–S battery is of paramount importance as the solid electrolyte interface (SEI) formed on the Ca anode limits the capacity and stability of the cell.

A hydroxylated graphene–S nanocomposite exhibiting superior electrochemical performance at high rates has been developed through a facile chemical deposition method at room temperature. The hydroxyl groups in graphene could interact with the sulfur-containing compounds, rendering sulfur in the amorphous state during the chemical deposition reaction and preventing polysulfide dissolution during cycling.

The morphology and the electronic properties of nano-textured “black” silicon, obtained by a metal-catalyzed wet etching process, and the improvement by an additional chemical treatment are examined with regard to solar cell applications. The improved nano-texture exhibits an optically graded surface with minimal surface area and a defect density comparable to planar c-Si wafers. Al₂O₃-passivated nano-textures, modified by the additional chemical treatment, show a tenfold higher effective lifetime.

The light collection in thin film polymer solar cells is substantially improved by application of a textured retroreflective foil, which reduces primary reflection and outcoupling of unabsorbed light. Consequently the external quantum efficiency (EQE) improves over the whole sensitivity range and the power conversion efficiency is improved by as much as 19%.

Strontium diffusion in magnetron sputtered gadolinia-doped ceria thin film is studied in a model system by X-ray diffraction and electron microscopy. The study shows that diffusion takes place along column boundaries and yields an in-depth understanding of the Sr diffusion mechanism. This study also demonstrates how to prepare efficient diffusion barriers for solid oxide fuel cells.

The role of additives in the development of morphology and microstructure in polymer–fullerene solar cells was revealed by in-situ spectroscopic ellipsometry and UV–vis transmission. The films were cast using a blade-based prototype for slot-die coating. The methods reveal the beginning and end of polymer solidification with ≈ 100 millisecond time resolution.

The power capability of the NASICON-type Li₃V₂(PO₄)₃ electrode is greatly improved by coating with PEDOT, that is, poly(3,4-ethylenedioxythiophene), a conducting polymer (see figure). The Li₃V₂(PO₄)₃/PEDOT electrode delivers more than 90% of its theoretical capacity (133 mAh g⁻¹) at 10 C rate and 97% of this capacity is retained at this rate after 100 cycles. This remarkable power and cycle stability achieved by a simple coating process makes this 4 V-class electrode one of the most promising electrode candidates for next-generation batteries.

The performance of small molecule organic photovoltaic cells shows a critical dependence on morphology and structure of the active layers. It is shown that fabrication parameters, like substrate temperature and device architecture, play a significant role for crystallization and roughening of the film and that these features are related to characteristic parameters of planar and planar-mixed heterojunction donor/acceptor cells under operation.

The incorporation of 3,6-carbazole units into photoactive copolymers results in conjugation breaks along the polymer backbones and thus in strong intermolecular interactions. Such copolymers provide thermally reproducible morphologies and enhanced device performances over a wide range of annealing temperatures, 100 to 160 °C, with high power conversion efficiencies of over 6%.

Molybdenum oxide oxidation states and their effect on the performance of bulk heterojunction polymer solar cells: UPS and XPS have shown that the presence of molybdenum oxide states below Mo⁵⁺ have severely detrimental effects on the performance of OPV's due to the occupation of the Mo4d orbital and pinning of the work function at a shallower energy.

Accurate optical modeling of solid-state dye sensitized solar cells is performed, accounting for various parasitic absorptions within the device. This optical modeling is used in conjunction with experimental measurements to measure the internal quantum efficiency (IQE) of solar cells. Measuring IQE for solar cells of varying thickness reveals that charge collection is efficient, but carrier injection is not.

ITO-free and fully solution-processed organic solar cells are demonstrated by employing AgNW as both the bottom and top electrodes, in conjunction with Al-ZnO and PEDOT:PSS as charge extraction layers. Devices with electrical FF up to 63.0% and fully retained V_oc are achieved, indicating that superior optoelectronic and film quality properties of the two interlayers are perfectly compatible to AgNW electrodes.

A method for efficiently screening a wide compositional and structural phase space of LISICON-type superionic conductors is presented that utilizes a machine-learning technique for combining theoretical and experimental datasets. By iteratively performing systematic sets of first-principles calculations and focused experiments, we show how the materials design process can be greatly accelerated, suggesting potentially superior candidate lithium superionic conductors.

Hybrid P3HT–Sb₂S₃ nanocomposite films are formed by means of an in-situ low-temperature thermal decomposition of a solution-processable antimony xanthate precursor in a polymer film. Transient optical spectroscopy and photovoltaic device studies suggest that charge separation and current generation in Sb₂S₃:P3HT based devices results mainly from Sb₂S₃ light absorption and subsequent hole-transfer from the inorganic semiconductor to the organic hole transporting material.

A pair of polymers, PBDTBT and PBDTDTBT, are synthesized for application in polymer solar cells (PSCs). With similar absorption bands and molecular energy levels, PBDTDTBT exhibits much better photovoltaic performance with power conversion efficiency (PCE) of 7.4%. To understand the differences between them, correlations of the molecular structure, morphology, dynamics and efficiency of these two polymers are investigated.

Interface recombination is explored in colloidal quantum dot photovoltaics. By using a thin ZnO buffer layer at the TiO₂-quantum dot interface, recombination is significantly reduced and performance gains of 10% are achieved through improved open circuit voltage and photocurrent extraction.

Poly(3-hexylthiophen-2,5-diyl) (P3HT), poly[(4,4′-bis(2-ethylhexyl)dithieno[3,2-b:2′,3′-d]silole)-2,6-diyl-alt-(4,7-bis(2-thienyl)-2,1,3-benzothiadiazole)-5,5′-diyl] (Si-PCPDTBT) and [6,6]-phenyl-C₆₁-butyric acid methyl ester (PC₆₁BM) ternary blend films are investigated in terms of morphology and photophysics. All experimental data consistently suggest that there is no large scale phase separation between the two polymers. A rapid transfer (100s of ps) of photo-generated positive polarons from the Si-PCPDTBT phase to the P3HT phase could be observed.

Highly efficient PbTe based thermoelectric materials are reported with maximal ZT values of ∼2, due to phase separation reactions resulted in sub-micro thermodynamically driven features. The reported materials are among the most efficient thermoelectric bulk materials ever reported.

Thin-film, microscale GaAs solar cells transfer printed into luminescent concentrating waveguides show significantly enhanced power output compared to cells evaluated in isolation. Experimental and numerical simulations results demonstrate that optimized configurations involve a free-standing waveguide and a diffuse backside reflector, as a way to maximize capture of both waveguided and scattered photons. Such unusual options in engineering design suggest promising additional avenues for use of luminescent concentration in advanced photovoltaics.

High power Li₄Ti₅O₁₂ (LTO) nanocrystals can be synthesized by a carbon-templating method for Li-ion battery electrodes. These electrodes demonstrate reversible cycling of 160 mAh/g at both 1 C and 10 C current, and remains above 150 mAh/g even at 100C.

A polymer solar cell with a power conversion efficiency up to 8% using a 200 nm thick active layer is demonstrated. While the external quantum efficiency increases with the thickness of the active layer, the decrease in fill factor is due to space charge accumulation which limits the device performance.

Despite advantages in availability and carbon sequestration, isolated chloroplasts remain unexplored as a renewable source for solar energy harvesting. One impediment is the diminished photosynthetic longevity due to photodamaging, reactive oxygen species (ROS) generation. This article demonstrates the first chloroplast-based biofuel cell. The effect of nanoparticle antioxidants on ROS generation is explored, and regenerative, dextran-wrapped nanoceria (dNC) are found to be the most effective of these agents.

The importance of domain purity and molecular orientation are investigated for solar cell devices based on naphtha[1,2-c:5,6-c]bis[1,2,5]thiadiazole (NT) or 2,1,3-benzothiadiazole based conjugated polymers. The results show that purer domains reduce bimolecular recombination. Molecular ordering of the polymer at the donor/acceptor interface is also observed and could be a critical parameter to explain high performance in organic solar cells. Both molecular ordering and domain purity should be widely considered to reveal structure-performance relationships.

Synchrotron radiation X-ray tomographic microscopy is performed on transition metal oxide-based porous electrodes to obtain statistically significant volume 3D reconstructions of the microstructure. A segmentation algorithm that allows identification of individual particles for electrochemical simulations is developed and implemented. The tomographic data (raw and processed) and the corresponding electrochemical data for 16 different cathodes is provided open source.

Transient photocurrent measurements provide an easy way of identifying the reasons for S-shapes in the current–voltage characteristics of (organic) solar cells. This method visualizing the redistribution of charges can be applied to explain the interplay between charge transport at the electrode and in the active material.

Shape-complementarity of donor and acceptor molecules drives self-assembly into an extended interface with a ball-and-socket structural motif, which increases both the active volume and exciton dissociation rates to improve the efficiency of organic solar cells.

An in-situ high-energy X-ray diffraction technique was deployed to investigate the thermal decomposition of a delithiated Li_1-x[Ni_1/3Mn_1/3Co_1/3]_0.9O₂ cathode during thermal abuse. A mechanism based on proton intercalation was proposed to explain the negative impact of LiPF₆ on the thermal stability of Li_1-x[Ni_1/3Mn_1/3Co_1/3]_0.9O₂.

The experimental specific capacitance of ruthenium oxide (RuO₂) is usually much smaller than the theoretical value due to low electron–proton transport and high rate dependence. Highly conductive nanoporous gold (NPG) can dramatically improve the capacitive performance of RuO₂ when RuO₂ is electroplated into NPG. The RuO₂@NPG electrodes provide fast ionic conduction and excellent electron–proton transport for low rate dependence and high charge storage of around 1500 F g⁻¹, close to the theoretical value of RuO₂.

Cyclized-polyacrylonitrile (cyclized-PAN) is used as a conformal coating on nano-Si for highly reversible anodes. Cyclization of PAN proceeds by limiting the pyrolysis to 300 °C such that our cyclized-PAN maintains its polymeric properties while also providing sp² π bonding for good electronic conductivity. Cyclized-PAN is thus a conjugated polymer with good mechanical resiliency to accommodate Si's volumetric expansion but also good mixed conductivity.

ITO free high efficiency polymer solar cells on opaque substrates such as steel are fabricated in conventional and inverted configurations using a high conductive PEDOT:PSS transparent top electrode and a silver collecting grid. The PEDOT:PSS top electrode is deposited using a stamp-transfer lamination technique, resulting in an essentially loss-free contact.

Inverted bulk heterojunction solar cells are fabricated using a conjugated polyelectrolyte (PFN) as a cathode interlayer. Enhanced photovoltaic performance is achieved by adjusting the PFN thickness. Measurements of the optical transmittance, cathode work function (via UPS) and surface atomic composition (via XPS) provide insights into this optimization. Drift-diffusion simulations point to a reduction in recombination of holes at the cathode as the main cause for improving V_oc.

A novel linear non-fullerene acceptor (DBS-2DPP) based on dibenzosilole and diketopyrrolopyrrole was designed and synthesized. DBS-2DPP exhibited strong and broad absorption and appropriate energy levels matching with P3HT. Solution-processed BHJ OSCs based on P3HT:DBS-2DPP showed PCEs as high as 2.05%.

Ultrahigh specific capacitance and excellent cyclic retention of MnO₂ can be achieved in a novel sandwich electrode loaded with a large amount of MnO₂ by utilizing the open porosity of dealloyed nanoporous metals. The highly conductive nanoporous metals, as both support of active materials and current collector of supercapactior, dramatically enhance the electronic/ionic conductivity and charge transfer at three phase interfaces.

Mechanisms of electrochemical processes in a cobaltite film are studied using dynamic electrochemical strain microscopy. The reversible oxygen reduction/evolution process starts at 3–4 V, and an irreversible process causing surface deformation manifests above 10–12 V. Post-mortem focused-ion beam milling and atomic resolution electron microscopy show that surface deformation is due to local amorphization.

The side-chain architecture of alternating copolymers based on thiophene and quinoxaline strongly influences the solubility and photovoltaic performance. In contrast to other donor polymers, the solubility as well as photovoltaic performance are maximized for the most disordered polymer that features a high degree of backbone twisting.

A new type of nitrogen-enriched carbon materials is synthesized from nitrile-rich alkali salts. High nitrogen content is obtained for these alkali salts precursors after annealing at 850 °C. These nitrogen-enriched carbons exhibit high coulombic efficiency, high reversible capacity and good cycling stability as anode materials for both mature lithium ion batteries and newly rejuvenated sodium ion batteries.

A novel facile filtration/wet transfer technique is developed for the fabrication of layered MoS₂/SWNTs porous thin films for lithium battery applications with excellent performance (992 mAh g⁻¹) and outstanding stability.

To overcome the cycling instability and inefficiency that are inherent to lithium–sulfur batteries, a conceptually new approach is adopted based on mitigating the sulfur loss by creating a dynamic equilibrium between the dissolution and precipitation of lithium polysulfides at the electrode interface. Novel lithium polysulfide electrolytes that play a major role in self-healing lithium–sulfur batteries are developed.

Hollow TiO₂ nanorods with surface coated with Fe₂O₃nanospikes are fabricated using atomic layer deposition and a sacrificial template. The LIB anode based on the obtained nanostructure exhibits a high reversible capacity (initial value 840 mAh g⁻¹), improved cycle stability (530 mAh g⁻¹ after 200 cycles at the current density of 200 mA g⁻¹) as well as outstanding rate capability.

A novel thin-film direct hydrogen peroxide/borohydride micro fuel cell with a high operating voltage of 1.6 V is fabricated by a facile method.

A promising new polyanion-based compound, Na_3.12M_2.44(P₂O₇)₂ (M=Fe, Fe_0.5Mn_0.5, Mn) is synthesized and examined as a cathode for Na ion batteries. Off-stoichiometric synthesis induces the formation of a Na-rich phase, Na_3.32Fe_2.34(P₂O₇)₂ which delivers a reversible capacity of about 85 mA h g⁻¹ at ca. 3 V vs. Na/Na⁺ with very stable cycle performance.

This article discusses the reasons for the decreased photovoltaic performance of absorber layers where polymers other than P3HT are blended with fullerene multiadducts like ICBA and bis-PCBM. It is found that the reduced performance is due to a mixture of reduced charge generation due to the smaller band offsets and reduced electron mobilities.

Upconverter-doped TiO₂ hollow shells prepared by a simple one-pot hydrothermal method can be used as a dual-functional top-layer in the photoanodes of dye-sensitized solar cells, not only improving the light scattering, but also enhancing near-infrared light harvesting of the DSSC cells.

Spatially separated CuInS₂ (CIS) surface regions of varying colors are observed and identified to be dominated by either CuS or Cu₂S phases. After removal, the chemical and electronic CIS surface structure still differs. Thus, for a systematic CIS material optimization towards higher-efficiency thin-film solar cells, the Cu_2-xS surface phase composition should be monitored/controlled.

Nickel gadolinium-doped ceria (Ni/GDC) solid oxide fuel cell (SOFC) anodes are studied in situ under methane electroxidation conditions using ambient pressure spectroscopies. The oxidation state and composition of the anode for optimal electrocatalytic performance are determined. The detailed mechanism of the voltage generation over Ni/GDC anodes is described by means of first principles calculations.

Cellulose, potato starch, and eucalyptus wood saw dust were transformed into porous carbons with micropore surface areas of up to 2387 m²/g. The specific capacitance of the produced carbons approaches 236 F/g (100 F/cc) when measured in a symmetric configuration in an organic electrolyte. Charge-discharge tests showed excellent capacitance retention with capacitance of up to 175 F/g at an ultra-high current density of 20 A/g.