Publications by Ulf Anders Hagfeldt

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Nickel oxide (NiOx) is a promising hole transport material in inverted organic-inorganic metal halide perovskite solar cells. However, its low intrinsic conductivity hinders its further improvement in device performance. Here, we employ a trimercapto-s-tri ...

The inward diffusion of metal electrodes is one of the main reasons for the deterioration of the long-term device stability of perovskite solar cells (PSCs). Thus, herein, we adopt a simple additive engineering strategy to modify the barrier material batho ...

Surface passivation treatment is a widely used strategy to resolve trap-mediated nonradiative recombination toward high-efficiency metal-halide perovskite photovoltaics. However, a lack of passivation with mixture treatment has been investigated, as well a ...

In this paper, spatially resolved photoluminescence (PL) spectroscopy with various excitation wavelengths is presented as a nondestructive and versatile technique providing access to the individual subcells of multijunction solar cells. This method is demo ...

Phenothiazine is a versatile scaffold frequently used in both pharmaceutical and photovoltaic applications. Still, the structural diversity within the class of phenothiazine sensitizers for dye-sensitized solar cells is minute. Substituents are found in 3, ...

Stabilized power output at maximum power point (mpp) has been considered as one of the most reliable parameters as it provides a key performance indicator for perovskite solar cells (PSCs) revealing the operational stability of the photovoltaic device. Her ...

The strategy of mixing cations and halides in hybrid organic lead halide perovskites has recently been shown to be very successful in achieving high efficiency with long-term perovskite solar cell stability. In this study, the effect of photoexcitation on ...

Record laboratory efficiencies of dye-sensitized solar cells have been recently reported using an alkoxysilyl-anchor dye, ADEKA-1 (over 14%). In this work we use time-resolved techniques to study the impact of key preparation factors (dye synthesis route, ...

Organo-metal halide perovskites (OMHPs) are materials with attractive properties for optoelectronics. They made a recent introduction in the photovoltaics world by methylammonium (MA) lead triiodide and show remarkably improved charge separation capabiliti ...

The use of molecular modulators to reduce the defect density at the surface and grain boundaries of perovskite materials has been demonstrated to be an effective approach to enhance the photovoltaic performance and device stability of perovskite solar cell ...

Oxides employed in halide perovskite solar cells (PSCs) have already demonstrated to deliver enhanced stability, low cost, and the ease of fabrication required for the commercialization of the technology. The most stable PSCs configuration, the carbon-base ...

Metal halide perovskites have thepotential to revolutionizethefield of photovoltaics, though limited stability has impeded commercialexploitation. The soft heterointerface between the perovskite andcharge-transporting layer is one of the major bottlenecks ...

With perovskite-based solar cells (PSCs) now reaching efficiencies of greater than 20 %, the stability of PSC devices has become a critical challenge for commercialization. However, most efficient hole-transporting materials (HTMs) thus far still rely on t ...

Perovskite solar cells (PSCs) have attracted unprecedented attention due to their rapidly rising photoelectric conversion efficiency (PCE). In order to further improve the PCE of PSCs, new possible optimization path needs to be found. Here, quasi-heterofac ...

The use of a solution process to grow perovskite thin films allows to extend the material processability. It is known that the physicochemical properties of the perovskite material can be tuned by altering the solution precursors as well as by controlling ...

Because of the compatibility with tandem devices and the ability to be manufactured at low temperatures, inverted perovskite solar cells have generated far-ranging interest for potential commercial applications. However, their efficiency remains inadequate ...

Novel unsym. org. sensitizers comprising donor, electron-conducting and anchoring groups were engineered at a mol. level and synthesized for sensitization of mesoscopic TiO2 injection solar cells. The unsym. org. sensitizers 3-(5-(4-(diphenylamino)styryl)t ...

Three classes (carbides, nitrides and oxides) of nanoscaled early-transition-metal catalysts have been proposed to replace the expensive Pt catalyst as counter electrodes (CEs) in dye-sensitized solar cells (DSCs). Of these catalysts, Cr3C2, CrN, VC(N), VN ...

The extension of the light absorption of photovoltaics into the near-infrared region is important to increase the energy conversion efficiency. Although the progress of the lead halide perovskite solar cells is remarkable, and high conversion efficiency of ...

Copper redox mediators can be employed in dye sensitized solar cells (DSCs) both as liquid electrolytes or as solid state hole transport materials (HTMs). The solid state devices that employ copper complex HTMs can be simply obtained by solvent evaporation ...

Ulf Anders Hagfeldt

Chat with Graph Search

Overcome Low Intrinsic Conductivity of NiOx Through Triazinyl Modification for Highly Efficient and Stable Inverted Perovskite Solar Cells

Inhibiting metal-inward diffusion-induced degradation through strong chemical coordination toward stable and efficient inverted perovskite solar cells

Surface Reconstruction Engineering with Synergistic Effect of Mixed‐Salt Passivation Treatment toward Efficient and Stable Perovskite Solar Cells

Nondestructive Probing of Perovskite Silicon Tandem Solar Cells Using Multiwavelength Photoluminescence Mapping

A comprehensive experimental study of five fundamental phenothiazine geometries increasing the diversity of the phenothiazine dye class for dye-sensitized solar cells

Power output stabilizing feature in perovskite solar cells at operating condition: Selective contact-dependent charge recombination dynamics

Photoinduced Lattice Symmetry Enhancement in Mixed Hybrid Perovskites and Its Beneficial Effect on the Recombination Behavior

Factors Affecting the Performance of Champion Silyl-Anchor Carbazole Dye Revealed in the Femtosecond to Second Studies of Complete ADEKA-1 Sensitized Solar Cells

Resonance Raman and Excitation Energy Dependent Charge Transfer Mechanism in Halide-Substituted Hybrid Perovskite Solar Cells

Crown Ether Modulation Enables over 23% Efficient Formamidinium-Based Perovskite Solar Cells

Interfacial Engineering of Metal Oxides for Highly Stable Halide Perovskite Solar Cells

Mitigating the Heterointerface Driven Instability in Perovskite Photovoltaics

Indeno[1,2-b]carbazole as Methoxy-Free Donor Group: Constructing Efficient and Stable Hole-Transporting Materials for Perovskite Solar Cells

Quasi-Heteroface Perovskite Solar Cells

Rapid hybrid perovskite film crystallization from solution

N-Type Conductive Small Molecule Assisted 23.5% Efficient Inverted Perovskite Solar Cells

Molecular Engineering of Organic Sensitizers for Dye-Sensitized Solar Cell Applications

Economical Pt-Free Catalysts for Counter Electrodes of Dye-Sensitized Solar Cells

Spectral splitting photovoltaics using perovskite and wideband dye-sensitized solar cells

Liquid State and Zombie Dye Sensitized Solar Cells with Copper Bipyridine Complexes Functionalized with Alkoxy Groups