Ulf Anders Hagfeldt

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Related publications (575)

Ultrahydrophobic 3D/2D fluoroarene bilayer-based water-resistant perovskite solar cells with efficiencies exceeding 22%

Shaik Mohammed Zakeeruddin, Jovana Milic, Yuhang Liu, Ulf Anders Hagfeldt, Mohammad Ibrahim Dar, Neha Arora, Linfeng Pan, Seckin Akin, Ryusuke Uchida, Alexander Roland Uhl

Preventing the degradation of metal perovskite solar cells (PSCs) by humid air poses a substantial challenge for their future deployment. We introduce here a two-dimensional (2D) A(2)PbI(4) perovskite layer using pentafluoro-phenylethylammonium (FEA) as a ...

2019

Improving energy transfer efficiency of dye-sensitized solar cell by fine tuning of dye planarity

Ulf Anders Hagfeldt

Two push-pull metal-free sensitizers with 5,11-dihydroindolo[3,2-b]carbazole derivatives as electron-donating groups and 4-(benzo[c][1,2,5]thiadiazol-4-ylethynyl)benzoic acid (BTZ) as electron-withdrawing unit, denoted by SK201 and SK202, were synthesized ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Performance of perovskite solar cells under simulated temperature-illumination real-world operating conditions

Michael Graetzel, Wolfgang Richard Tress, Ulf Anders Hagfeldt, Konrad Domanski, Essa Awadh R Alharbi, Brian Irving Carlsen, Anand Agarwalla

Since reaching 20% efficiency, research in perovskite photovoltaics has shifted from a race for efficiency to a race for stability. For efficiency, the standard test conditions set the rules for the race. However, the term 'stability' is used very broadly ...

NATURE PUBLISHING GROUP2019

Boosting the power conversion efficiency of perovskite solar cells to 17.7% with an indolo[3,2-b]carbazole dopant-free hole transporting material by improving its spatial configuration

Xiaoqing Jiang, Ulf Anders Hagfeldt

The development of facilely synthesized, dopant-free hole-transporting materials (HTMs) with high efficiency is of great significance for the potential application of perovskite solar cells (PSCs). Herein, we report two novel indolo[3,2-b]carbazole (ICZ) b ...

ROYAL SOC CHEMISTRY2019

Synergistic Crystal and Interface Engineering for Efficient and Stable Perovskite Photovoltaics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Michael Saliba, Pankaj Kumar Yadav, Mohammad Mahdi Tavakoli, Philippe Jürgen Holzhey

The presence of bulk and surface defects in perovskite light harvesting materials limits the overall efficiency of perovskite solar cells (PSCs). The formation of such defects is suppressed by adding methylammonium chloride (MACl) as a crystallization aid ...

WILEY-V C H VERLAG GMBH2019

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Dye-sensitized solar cells (DSSCs) have attracted a substantial interest in the last 30 years for the conversion of solar power to electricity. An important component is the redox mediator effecting the transport of charge between the photoelectrode and th ...

2019

Perovskite solar cells (PSCs) reached a certified 23.7% efficiency in 2018 by boosting their surprisingly high open-circuit voltage (V-OC) and photocurrent. The suppressed recombination in PSCs significantly cut down the voltage loss between the bandgap en ...

ROYAL SOC CHEMISTRY2019

Design, synthesis and characterization of 1,8-naphthalimide based fullerene derivative as electron transport material for inverted perovskite solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Hui-Seon Kim

A new fullerene derivative, PC61BNI, was designed and synthesized in which [6,6]-phenyl C-61-butyric acid methyl ester (PC61BM) was modified by replacing the methyl group with 1,8-naphthalimide (NI) to investigate the molecular structure modification effec ...

ELSEVIER SCIENCE SA2019

Europium-Doped CsPbI2Br for Stable and Highly Efficient Inorganic Perovskite Solar Cells

Michael Graetzel, David Lyndon Emsley, Giovanni Dietler, Wolfgang Richard Tress, Ulf Anders Hagfeldt, Jingshan Luo, Dominik Józef Kubicki, Daniel Prochowicz, Zaiwei Wang, Jiangtao Zhou, Seckin Akin, Wanchun Xiang

All-inorganic perovskite films hold promise for improving the stability of perovskite solar cells (PSCs). However, the 3D alpha phase of narrow-bandgap inorganic perovskites is thermodynamically unstable at room temperature, limiting the development of hig ...

CELL PRESS2019

Perovskite Solar Cells Based on Oligotriarylamine Hexaarylbenzene as Hole-Transporting Materials

Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Mona Shasti

A cobalt-catalyzed cyclotrimerization of bis(aryl)alkyne is used as an innovative tool to obtain hole-transport materials (HTMs). The novel HTM containing six units of oligotriarylamine (HAB1), characterized by UV-vis, cyclic voltammetry, DFT, and thermogr ...

AMER CHEMICAL SOC2019

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