Publications by Ulf Anders Hagfeldt

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Dye-sensitized solar cells (DSCs) based on copper(II/I) redox mediators have recently achieved notable performance progress through tailoring the ligand structure of the copper complexes, exploiting cosensitization, and introducing an advanced device struc ...

There exists a considerable density of interaggregate grain boundaries (GBs) and intra-aggregate GBs in polycrystalline perovskites. Mitigation of intra- aggregate GBs is equally notable to that of interaggregate GBs as intra-aggregate GBs can also cause d ...

The impact of the dye architecture on the kinetics in the dyesensitized solar cell (DSC) was investigated for two structurally similar organic dyes, adsorbed adsorbed to a mesoporous TiO2 film. Differences in the HOMO and LUMO levels of the triphenylamine ...

Two new electron-rich molecules, 2,3,4,5-tetra[4,4'-bis(methoxyphenyl)aminophen-4 ''-yl]-thiophene (H111) and 4,4',5,5'-tetra[4,4'-bis(methoxyphenyl) aminophen-4 ''-yl]-2,2'-bithiophene (H112), which contain thiophene cores with arylamine side groups, are ...

Nonradiative recombination is a major limiting factor in obtaining efficient metal-halide perovskite photovoltaics. Here, a passivation treatment is developed by applying a mixture of a new ammonium salt, CF3(CF2)(2)CH2NH3I (HBAI), and a conventional forma ...

To improve the catalytic activity of Nb2O5, a composite Nb2O5/C (Nb2O5 imbedded in carbon support) is synthesized with a simple in situ method and then introduced the composite into dye-sensitized solar cells (DSCs) as a counter electrode (CE) catalyst. Ba ...

Formamidinium lead iodide perovskites are promising light-harvesting materials, yet stabilizing them under operating conditions without compromising optimal optoelectronic properties remains challenging. We report a multimodal host–guest complexation strat ...

The power-conversion efficiencies (PCEs) of perovskite solar cells (PSCs) have increased rapidly from about 4% to 22% during the past few years. One of the major challenges for further improvement of the efficiency of PSCs is the lack of sufficiently good ...

The past several years have witnessed the rapid emergence of a class of solar cells based on mixed organic-inorganic halide perovskites. Today's state-of-the-art perovskite solar cells (PSCs) employ various methods to enhance nucleation and improve the smo ...

The use of layered perovskites is an important strategy to improve the stability of hybrid perovskite materials and their optoelectronic devices. However, tailoring their properties requires accurate structure determination at the atomic scale, which is a ...

Pt3Ni alloy supported by carbon nanofibers (CNs) composites (Pt3Ni/CNs) synthesized by a simple solvothermal process was introduced into dye-sensitized solar cells (DSCs) as counter electrode (CE) for the first time, and the DSCs based on Pt3Ni/CNs CE obta ...

Mixed-ion (FAPbI(3))(1-x)(MAPbBr(3))(x) perovskite solar cells have achieved power conversion efficiencies surpassing 20%. However, in order to obtain these high efficiencies the preparation is performed in a controlled inert atmosphere. Here, we report a ...

The present invention relates to a redox copper complex melt comprising a metalorganic complex of formula (I) [Cu (La) n ] (I), wherein n is an integer 2; and La is a bidentate ligand selected from a ligand according to any one of formulae (1) and (2): ...

A new tandem electrolyte composed of two redox pairs, the organic radical 2-azaadamantane-N-oxyl (AZ) and the well-known redox pair Co(bpy)(3) was investigated in dye sensitized solar cells. Importantly, an increase in V-OC was achieved using the ...

Layered hybrid perovskites comprising adamantyl spacer (A) cations based on the A(2)FA(n-1)Pb(n)I(3n+1)(n= 1-3, FA = formamidinium) compositions have recently been shown to act as promising materials for photovoltaic applications. While the corresponding p ...

The effect of Cs-incorporated NiOx on perovskite solar cells with an inverted structure was investigated, where NiOx and PCBM were used as selective contacts for holes and electrons, respectively. It was found that the generation of an Ni phase in an NiOx ...

Nanocrystalline tin (iv) oxide (SnO2) electron-transport layers (ETL) have shown great potential for achieving highly efficient, stable perovskite solar cells (PSCs), in particular low-temperature-processed flexible PSCs. Recently, studies have further sho ...

Electrochemical reduction of carbon dioxide, if powered by renewable electricity, could serve as a sustainable technology for carbon recycling and energy storage. Among all the products, ethanol is an attractive liquid fuel. However, the maximum faradaic e ...

Photoelectrochemical approach to solar energy conversion demands a kinetic optimization of various light-induced electron transfer processes. Of great importance are the redox mediator systems accomplishing the electron transfer processes at the semiconduc ...

Ulf Anders Hagfeldt

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Blue Photosensitizer with Copper(II/I) Redox Mediator for Efficient and Stable Dye‐Sensitized Solar Cells

Enabling full-scale grain boundary mitigation in polycrystalline perovskite solids

Influence of Dye Architecture of Triphenylamine Based Organic Dyes on the Kinetics in Dye-Sensitized Solar Cells

Hole-Transporting Small Molecules Based on Thiophene Cores for High Efficiency Perovskite Solar Cells

Reinforced polypyrrole with 2D graphene flakes decorated with interconnected nickel-tungsten metal oxide complex toward superiorly stable supercapacitor (vol 418, 129396, 2021)

Outstanding Passivation Effect by a Mixed-Salt Interlayer with Internal Interactions in Perovskite Solar Cells

Highly efficient dye-sensitized solar cells achieved through using Pt-free Nb2O5/C composite counter electrode and iodide-free redox couples

Multimodal host–guest complexation for efficient and stable perovskite photovoltaics

Tailor-Making Low-Cost Spiro[fluorene-9,9 '-xanthene]-Based 3D Oligomers for Perovskite Solar Cells

Polymer-templated nucleation and crystal growth of perovskite films for solar cells with efficiency greater than 21%

Nanoscale Phase Segregation in Supramolecular π-Templating for Hybrid Perovskite Photovoltaics from NMR Crystallography

Low-cost Cr doped Pt3Ni alloy supported on carbon nanofibers composites counter electrode for efficient dye-sensitized solar cells

Ambient air-processed mixed-ion perovskites for high-efficiency solar cells

Redox melts formed by copper (i)/(ii) complexes as charge transfer and charge storage materials

A tandem redox system with a cobalt complex and 2-azaadamantane-N-oxyl for fast dye regeneration and open circuit voltages exceeding 1 V

Unravelling the structural complexity and photophysical properties of adamantyl-based layered hybrid perovskites

Effect of Cs-Incorporated NiOx on the Performance of Perovskite Solar Cells

Modulation of perovskite crystallization processes towards highly efficient and stable perovskite solar cells with MXene quantum dot-modified SnO2

Atomic Layer Deposition of ZnO on CuO Enables Selective and Efficient Electroreduction of Carbon Dioxide to Liquid Fuels

A small electron donor in cobalt complex electrolyte significantly improves efficiency in dye-sensitized solar cells