Publications by Bowen Yang | EPFL Graph Search

Related publications (30)

Perovskite Solar Cells with Carbon-Based Electrodes - Quantification of Losses and Strategies to Overcome Them

Ulf Anders Hagfeldt, Bowen Yang, Jiajia Suo

Carbon-based electrodes represent a promising approach to improve stability and up-scalability of perovskite photovoltaics. The temperature at which these contacts are processed defines the absorber grain size of the perovskite solar cell: in cells with lo ...

WILEY-V C H VERLAG GMBH2022

When photoluminescence, electroluminescence, and open-circuit voltage diverge - light soaking and halide segregation in perovskite solar cells

Ulf Anders Hagfeldt, Wolfgang Richard Tress, Bowen Yang, Yeonju Kim

Perovskite solar cells suffer from various instabilities on all time scales. Some of them are driven by light, in particular when employing compounds with mixed halides. Such light soaking effects have been observed to result in performance changes of sola ...

Royal Society of Chemistry2021

Polymeric room-temperature molten salt as a multifunctional additive toward highly efficient and stable inverted planar perovskite solar cells

Ulf Anders Hagfeldt, Bowen Yang, Jiajia Suo

The inferior power conversion efficiency (PCE) compared to their regular counterparts (n-i-p) and undesirable stability issues of inverted (p-i-n) perovskite solar cells (PSCs) are the foremost issues hindering their commercialization. Here, for the first ...

ROYAL SOC CHEMISTRY2020

Low-temperature carbon-based electrodes in perovskite solar cells

Ulf Anders Hagfeldt, Bowen Yang, Jaekeun Lim

Carbon-based electrodes have been widely applied in perovskite solar cells (PSCs) because of their chemical inertness and compatibility with up-scalable techniques, signifying their solid potential for mass-production. The material scarcity and complexity ...

ROYAL SOC CHEMISTRY2020

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

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

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

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

Ulf Anders Hagfeldt, Hui Chen, 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

Interfacial Passivation Engineering of Perovskite Solar Cells with Fill Factor over 82% and Outstanding Operational Stability on n-i-p Architecture

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Bowen Yang, Yeonju Kim, Jiajia Suo

Tremendous efforts have been dedicated toward minimizing the open-circuit voltage deficits on perovskite solar cells (PSCs), and the fill factors are still relatively low. This hinders their further application in large scalable modules. Herein, we employ ...

AMER CHEMICAL SOC2021

Formation of High-Performance Multi-Cation Halide Perovskites Photovoltaics by delta-CsPbI3/delta-RbPbI3 Seed-Assisted Heterogeneous Nucleation

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mounir Driss Mensi, Ulf Anders Hagfeldt, Thomas Paul Baumeler, Linfeng Pan, Essa Awadh R Alharbi, Zaiwei Wang, Masaud Hassan S Almalki, Bowen Yang, Felix Thomas Eickemeyer, Anurag Krishna, Olivier Ouellette

The performance of perovskite solar cells is highly dependent on the fabrication method; thus, controlling the growth mechanism of perovskite crystals is a promising way towards increasing their efficiency and stability. Herein, a multi-cation halide compo ...

2021

Urea Derivative-Promoted CsPbl(2)Br Perovskite Solar Cells with High Open-Circuit Voltage

Bowen Yang

Inorganic perovskite solar cells (PSCs) have witnessed extraordinary advances owing to their prominent stability against thermal aging. However, they suffer from a phase transition from black phase to yellow phase under ambient conditions and serious energ ...

WILEY-V C H VERLAG GMBH2022

Methylammonium Triiodide for Defect Engineering of High-Efficiency Perovskite Solar Cells

Michael Graetzel, Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Mounir Driss Mensi, Ursula Röthlisberger, Ulf Anders Hagfeldt, Thomas Paul Baumeler, Linfeng Pan, Paramvir Ahlawat, Claudia Esther Avalos, Essa Awadh R Alharbi, Pascal Alexander Schouwink, George Cameron Fish, Mathias Dankl, Bowen Yang, Felix Thomas Eickemeyer, Viktor Skorjanc, Anurag Krishna, Olivier Ouellette, Lukas Pfeifer

The defects present in metal halide perovskite are deleterious to both the performance and stability of photovoltaic devices. Consequently, there is an intense focus on developing defect mitigation strategies. Herein we report a facile strategy that employ ...

2021

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

Ulf Anders Hagfeldt, Hui Chen, Bowen Yang

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 ...

WILEY-V C H VERLAG GMBH2022

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

Ulf Anders Hagfeldt, Bowen Yang

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 ...

ROYAL SOC CHEMISTRY2022

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, 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

Zinc Phthalocyanine Conjugated Dimers as Efficient Dopant-Free Hole Transporting Materials in Perovskite Solar Cells

Ulf Anders Hagfeldt, Kazuteru Nonomura, Natalie Flores Diaz, Brian Irving Carlsen, Marco Alejandro Ruiz Preciado, Bowen Yang, Felix Thomas Eickemeyer

Four ZnPc-dimers with 2,5-thienyl (ZnPc-th-ZnPc 1), 2,7-fluorenyl (ZnPc-flu-ZnPc 2), 3,6-bisthienylldiketopyrrolopyrrole (ZnPc-DPP-ZnPc 3) and 1,4-phenyl (ZnPc-p-ZnPc 4) bridges have been studied as dopant-free hole transporting materials (HTMs) in perovsk ...

WILEY-V C H VERLAG GMBH2020

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

Ulf Anders Hagfeldt, Hui Chen, Xiong Li, 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

A universal ligand for lead coordination and tailored crystal growth in perovskite solar cells

Ulf Anders Hagfeldt, Bowen Yang, Jiajia Suo

Chemical environment and precursor-coordinating molecular interactions within a perovskite precursor solution can lead to important implications in structural defects and crystallization kinetics of a perovskite film. Thus, the opto-electronic quality of s ...

Royal Soc Chemistry2024

Interfacial versus Bulk Properties of Hole-Transporting Materials for Perovskite Solar Cells: Isomeric Triphenylamine-Based Enamines versus Spiro-OMeTAD

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

Here, we report on three new triphenylamine-based enamines synthesized by condensation of an appropriate primary amine with 2,2-diphenylacetaldehyde and characterized by experimental techniques and density functional theory (DFT) computations. Experimental ...

AMER CHEMICAL SOC2021

Molecularly Engineered Low-Cost Organic Hole-Transporting Materials for Perovskite Solar Cells: The Substituent Effect on Non-fused Three-Dimensional Systems

Michael Graetzel, Shaik Mohammed Zakeeruddin, Nikolaos Vlachopoulos, Ulf Anders Hagfeldt, Brian Irving Carlsen, Bowen Yang, Jiajia Suo

In this work, we describe a new class of non-fused 3D asymmetric compounds (named 1, 2, 3, and 4) as low-cost organic hole-transporting materials (HTMs) for perovskite solar cells (PSCs). The fundamental understanding of the influence of the methylthio and ...

AMER CHEMICAL SOC2022