Recherche

Afficher tous les résultats pour

Accueil

Personne

Ulf Anders Hagfeldt

Cette personne n’est plus à l’EPFL

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (296)

Intermediate phase engineering of halide perovskites for photovoltaics

Ulf Anders Hagfeldt, Zaiwei Wang, Wanchun Xiang, Jiahuan Zhang

Metal halide perovskites serving as one of the most promising photovoltaic materials are gaining considerable attention worldwide. For achieving high performance as well as long-term stability of the perovskite solar cells (PSCs), a good quality of perovsk ...

CELL PRESS2022

In Operando, Photovoltaic, and Microscopic Evaluation of Recombination Centers in Halide Perovskite-Based Solar Cells

Ulf Anders Hagfeldt, Henry Snaith, Silver Hamill Turren Cruz

The origin of the low densities of electrically active defects in Pb halide perovskite (HaP), a crucial factor for their use in photovoltaics, light emission, and radiation detection, remains a matter of discussion, in part because of the difficulty in det ...

AMER CHEMICAL SOC2022

Thiocyanate-Mediated Dimensionality Transformation of Low- Dimensional Perovskites for Photovoltaics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Claudia Esther Avalos, Zaiwei Wang, Yuhang Liu, Brian Irving Carlsen, Jovana Milic, Dan Ren

Two-dimensional (2D) hybrid perovskite solar cells have induced widespread research interest owing to their higher stability as compared to three-dimensional (3D) analogues. The photovoltaic performance, however, is still limited. Here, we report a perovsk ...

2022

Ion-modulated radical doping of spiro-OMeTAD for more efficient and stable perovskite solar cells

Ulf Anders Hagfeldt, Bowen Yang, Jiajia Suo

Record power conversion efficiencies (PCEs) of perovskite solar cells (PSCs) have been obtained with the organic hole transporter 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9'-spirobifluorene (spiro-OMeTAD). Conventional doping of spiro-OMeTAD with ...

American Association for the Advancement of Science2022

Hysteresis-Free Planar Perovskite Solar Module with 19.1% Efficiency by Interfacial Defects Passivation

Ulf Anders Hagfeldt, Bowen Yang, Jiajia Suo

In few years, perovskite solar devices have reached high efficiency on lab scale cells. Upscaling to module size, effective perovskite recipe and posttreatment are of paramount importance to the breakthrough of the technology. Herein this work, the develop ...

WILEY-V C H VERLAG GMBH2022

Resurgence of DSCs with copper electrolyte: a detailed investigation of interfacial charge dynamics with cobalt and iodine based electrolytes (vol 6, pg 22204, 2018)

Ulf Anders Hagfeldt

Correction for 'Resurgence of DSCs with copper electrolyte: a detailed investigation of interfacial charge dynamics with cobalt and iodine based electrolytes' by Sourava C. Pradhan et al., J. Mater. Chem. A, 2018, 6, 22204-22214, DOI: 10.1039/C8TA06948D. ...

Royal Society of Chemistry2022

Deconvolution of Light-Induced Ion Migration Phenomena by Statistical Analysis of Cathodoluminescence in Lead Halide-Based Perovskites

Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Ulf Anders Hagfeldt, Nicolas Tappy, Erfan Shirzadi

Studying the compositional instability of mixed ion perovskites under light illumination is important to understand the mechanisms underlying their efficiency and stability. However, current techniques are limited in resolution and are unable to deconvolut ...

WILEY2022

N-coordinated bimetallic defect-rich nanocarbons as highly efficient electrocatalysts in advanced energy conversion applications

Ulf Anders Hagfeldt, Sining Yun

Defect engineering in heterostructured carbon-based electrode materials has evolved as an emerging strategy to boost the electrocatalytic activity. Herein, a facile single-step route is reported to synthesize novel N-coordinated bimetal doped graphitic car ...

ELSEVIER SCIENCE SA2022

Additives-free indolo[3,2-b]carbazole-based hole-transporting materials for perovskite solar cells with three yeses: Stability, efficiency, simplicity

Ulf Anders Hagfeldt, Bowen Yang, Yeonju Kim, Jiajia Suo

Indolo[3,2-b]carbazole-based hole transporting materials (HTM1-3) are developed for dopant-free pemvskite solar cells (PSCs). The newly synthesized compounds are studied as alternatives of conventional hole-transporting materials which typically require ad ...

Elsevier2022

An open-access database and analysis tool for perovskite solar cells based on the FAIR data principles

Ulf Anders Hagfeldt, Barbara Alexandra Primera Darwich, Bowen Yang

Making large datasets findable, accessible, interoperable and reusable could accelerate technology development. Now, Jacobsson et al. present an approach to build an open-access database and analysis tool for perovskite solar cells. ...

NATURE PORTFOLIO2022

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

Ulf Anders Hagfeldt, Hui Chen, Jiabao Yang, Hadi Salari, Xiong Li, Tong Wang, Bowen Yang

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 ...

WILEY-V C H VERLAG GMBH2022

Enabling full-scale grain boundary mitigation in polycrystalline perovskite solids

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Jingshan Luo, Lichen Zhao, Yuhang Liu, Felix Thomas Eickemeyer

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 ...

AMER ASSOC ADVANCEMENT SCIENCE2022

Deep defect passivation and shallow vacancy repair via an ionic silicone polymer toward highly stable inverted perovskite solar cells

Ulf Anders Hagfeldt, Hui Chen, Jiabao Yang, Tong Wang, Bowen Yang

Additive engineering is an effective strategy for defect passivation and performance improvement of perovskite solar cells (PSCs). However, few additives have achieved outstanding stability with high efficiency by simultaneously passivating deep and shallo ...

ROYAL SOC CHEMISTRY2022

Structural and Compositional Investigations on the Stability of Cuprous Oxide Nanowire Photocathodes for Photoelectrochemical Water Splitting

Michael Graetzel, Ulf Anders Hagfeldt, Linfeng Pan

Cuprous oxide (Cu2O) is a promising photocathode material for photoelectrochemical (PEC) water splitting. Recently, the PEC performances of Cu2O-based devices have been considerably improved by introducing nanostructures, semiconductor overlayers, and hydr ...

AMER CHEMICAL SOC2021

Water Stable Haloplumbate Modulation for Efficient and Stable Hybrid Perovskite Photovoltaics

Michael Graetzel, Ulf Anders Hagfeldt, Zaiwei Wang, Jovana Milic

The commercialization of perovskite solar cells is mainly limited by their operational stability. Interlayer modification by thin interface materials between the perovskite and the charge transport layers is one of the most effective methods to promote the ...

WILEY-V C H VERLAG GMBH2021

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

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Yuhang Liu, Tian Chen, Haizhou Lu, Jaeki Jeong

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 ...

2021

Multimodal host–guest complexation for efficient and stable perovskite photovoltaics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Ulf Anders Hagfeldt, Marko Mladenovic, David Lyndon Emsley, Farzaneh Jahanbakhshi, Paramvir Ahlawat, Zaiwei Wang, Jovana Milic, Dan Ren, Aditya Mishra, Felix Thomas Eickemeyer, Hong Zhang, Zhaowen Dong, Jinming Guo, Michael Allan Hope, Anurag Krishna, Olivier Ouellette, Tzu-Sen Su, Zhiwen Zhou

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 ...

Nature Research2021

New approaches in component design for dye-sensitized solar cells

Nikolaos Vlachopoulos, Ulf Anders Hagfeldt

The present perspective presents a number of issues related to the current direction of DSSC research, with emphasis on the transition from iodide-containing electrolyte to charge-transport media (CTMs), electrolytes or solid-state conductors based on inor ...

ROYAL SOC CHEMISTRY2021

Chemically tailored molecular surface modifiers for efficient and stable perovskite photovoltaics

Michael Graetzel, Ulf Anders Hagfeldt, Yuhang Liu, Bitao Dong

Perovskite solar cells (PSCs) have attracted intense attention based on their high power conversion efficiency and low production cost. However, due to the polycrystalline nature and the intrinsic hydrophilicity of the metal halide perovskite moieties, the ...

WILEY2021

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

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Filippo de Angelis, Hui-Seon Kim, Bowen Yang, Yeonju Kim, Jiajia Suo

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 ...

2021

Page 2 sur 15