Publications de Jiajia Suo | EPFL Graph Search

Multifunctional sulfonium-based treatment for perovskite solar cells with less than 1% efficiency loss over 4,500-h operational stability tests

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

The stabilization of grain boundaries and surfaces of the perovskite layer is critical to extend the durability of perovskite solar cells. Here we introduced a sulfonium-based molecule, dimethylphenethylsulfonium iodide (DMPESI), for the post-deposition tr ...

Nature Portfolio2024

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

Hydroxamic acid pre-adsorption raises the efficiency of cosensitized solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Nikolaos Vlachopoulos, Ulf Anders Hagfeldt, Yiming Cao, Felix Thomas Eickemeyer, Yameng Ren, Dan Zhang, Jiajia Suo

Dye-sensitized solar cells (DSCs) convert light into electricity by using photosensitizers adsorbed on the surface of nanocrystalline mesoporous titanium dioxide (TiO2) films along with electrolytes or solid charge-transport materials(1-3). They possess ma ...

NATURE PORTFOLIO2023

Interfacial engineering from material to solvent: A mechanistic understanding on stabilizing alpha-formamidinium lead triiodide perovskite photovoltaics

Michael Graetzel, Ulf Anders Hagfeldt, Bowen Yang, Jiajia Suo, Jaeki Jeong

Formamidinium lead triiodide (FAPbI3) has recently been considered as the most promising candidate to achieve highly efficient perovskite solar cells (PSCs). Excitingly, the state-of-the-art highest efficiency of FAPbI3 based PSCs have reached over 25%. Ho ...

Elsevier2022

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

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

Ulf Anders Hagfeldt, Dmitry Bogachuk, 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

Strain effects on halide perovskite solar cells

Mohammad Khaja Nazeeruddin, Ulf Anders Hagfeldt, Hobeom Kim, Bowen Yang, Jiajia Suo

Halide perovskite solar cells (PSCs) have achieved power conversion efficiencies (PCEs) approaching 26%, however, the stability issue hinders their commercialization. Due to the soft ionic nature of perovskite materials, the strain effect on perovskite fil ...

Royal Society of Chemistry2022

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

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

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

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

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

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

Ulf Anders Hagfeldt, Wolfgang Richard Tress, Filippo de Angelis, Hui-Seon Kim, Bowen Yang, Jiajia Suo

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 ...

AMER CHEMICAL SOC2020

Revealing the Mechanism of Doping of spiro-MeOTAD via Zn Complexation in the Absence of Oxygen and Light

Ulf Anders Hagfeldt, Yasemin Saygili, Hui-Seon Kim, Bowen Yang, Jiajia Suo

In this study, a new mechanism for doping of spiro-MeOTAD by Zn(TFSI)(2) is revealed, which is completely different from the mechanism induced by LiTFSI. The oxidation of spiro-MeOTAD is facilitated by complexation between the zinc cation and tert-butylpyr ...

AMER CHEMICAL SOC2020

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

Ulf Anders Hagfeldt, Jiabao Yang, Ziwei He, Bowen Yang, Jiajia Suo, Chao Tang, Shilong Wang

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