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Zaiwei Wang

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Related publications (26)

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Ti-1-graphene single-atom material for improved energy level alignment in perovskite solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Zaiwei Wang, Felix Thomas Eickemeyer, Hongwei Zhu

Carbon-based perovskite solar cells (C-PSCs) are widely accepted as stable, cost-effective photovoltaics. However, C-PSCs have been suffering from relatively low power conversion efficiencies (PCEs) due to severe electrode-related energy loss. Herein, we r ...

2021

Intermediate Phase Enhances Inorganic Perovskite and Metal Oxide Interface for Efficient Photovoltaics

Michael Graetzel, Ulf Anders Hagfeldt, Dominik Józef Kubicki, Wolfgang Richard Tress, David Lyndon Emsley, Claudia Esther Avalos, Zaiwei Wang, Yuhang Liu, Anand Agarwalla, Brian Irving Carlsen, Aditya Mishra, Haizhou Lu

Interfacial modification is crucial to fully develop the potential of semiconductor devices, including the revolutionary halide perovskite-based optoelectronics, such as photovoltaics, light-emitting diodes, and photodetectors. The all-inorganic halide per ...

CELL PRESS2020

How far does the defect tolerance of lead-halide perovskites range? The example of Bi impurities introducing efficient recombination centers

Björn Niesen, Simone Meloni, Wolfgang Richard Tress, Juan-Pablo Correa-Baena, Zaiwei Wang, Chien-Jen Yang

One of the key properties of lead-halide perovskites employed in solar cells is the defect tolerance of the materials, in particular regarding intrinsic point defects, which mainly form shallow traps. Considering that high luminescence yields and photovolt ...

Royal Society of Chemistry2019

SnS Quantum Dots as Hole Transporter of Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Peng Wang, Zaiwei Wang, Yuhang Liu, Yang Li, Dan Ren

Perovskite solar cells have achieved comparable power conversion efficiencies as commercial silicon cells, making the issue of long-term operation stability as the most critical scientific factor toward industrial realization. In this work, we introduce Sn ...

AMER CHEMICAL SOC2019

Decoupling the effects of defects on efficiency and stability through phosphonates in stable halide perovskite solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Dominik Józef Kubicki, David Lyndon Emsley, Hui-Seon Kim, Zaiwei Wang, Anand Agarwalla

Understanding defects is of paramount importance for the development of stable halide perovskite solar cells (PSCs). However, isolating their distinctive effects on device efficiency and stability is currently a challenge. We report that adding the organic ...

CELL PRESS2021

Ligand-Modulated Excess PbI2 Nanosheets for Highly Efficient and Stable Perovskite Solar Cells

Ulf Anders Hagfeldt, Chenyi Yi, Jingshan Luo, Zaiwei Wang

Excess lead iodide (PbI2), as a defect passivation material in perovskite films, contributes to the longer carrier lifetime and reduced halide vacancies for high-efficiency perovskite solar cells. However, the random distribution of excess PbI2 also leads ...

Wiley-V C H Verlag Gmbh2020

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

Hydrophobic Organic Ammonium Halide Modification toward Highly Efficient and Stable CsPbI(2.25)Br(0.75 )Solar Cell

Ulf Anders Hagfeldt, Zaiwei Wang

Inorganic cesium lead halide perovskite solar cells are promising candidates for next-generation photovoltaic applications. However, their phase instability and relatively low efficiency hinder their commercialization. Herein, hydrophobic organic ammonium ...

WILEY-V C H VERLAG GMBH2021

Formation and stabilization of all-inorganic perovskites for photovoltaics

Zaiwei Wang

All-inorganic perovskite films hold promise for improving stability of perovskite solar cells. However, the desirable narrow-bandgap inorganic perovskites (such as CsPbI3 and CsPbI2Br) are suffering from the thermodynamic phase instability, as the photoact ...

EPFL2020

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

Transient Photovoltage Measurements on Perovskite Solar Cells with Varied Defect Concentrations and Inhomogeneous Recombination Rates

Wolfgang Richard Tress, Zaiwei Wang, Brian Irving Carlsen

In all kinds of solar cells, transient photovoltage (TPV) decay measurements have been used to determine charge carrier lifetimes and to quantify recombination processes and orders. However, in particular, for thin-film devices with a high capacitance, the ...

2020

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

Nikolaos Vlachopoulos, Ulf Anders Hagfeldt, Wolfgang Richard Tress, Kazuteru Nonomura, Hui-Seon Kim, Zaiwei Wang, Anna Morales Melgares

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 ...

WILEY2018

Ba-induced phase segregation and band gap reduction in mixed-halide inorganic perovskite solar cells

Michael Graetzel, Ulf Anders Hagfeldt, Dominik Józef Kubicki, Wolfgang Richard Tress, Jingshan Luo, David Lyndon Emsley, Albert Hofstetter, Zaiwei Wang

All-inorganic metal halide perovskites are showing promising development towards efficient long-term stable materials and solar cells. Element doping, especially on the lead site, has been proved to be a useful strategy to obtain the desired film quality a ...

Nature Research2019

PbZrTiO3 ferroelectric oxide as an electron extraction material for stable halide perovskite solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Michael Saliba, Hui-Seon Kim, Zaiwei Wang, Anna Morales Melgares

State-of-the-art halide perovskite solar cells employ semiconductor oxides as electron transportmaterials. Defects in these oxides, such as oxygen vacancies (Ovac), act as recombination centres and, in air and UV light, reduce the stability of the solar ce ...

2019

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

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

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

Highly efficient, stable and hysteresis-less planar perovskite solar cell based on chemical bath treated Zn2SnO4 electron transport layer

Michael Graetzel, Ulf Anders Hagfeldt, Wolfgang Richard Tress, Zaiwei Wang, Seckin Akin, Marco Alejandro Ruiz Preciado

The electron transport layer (ETL) is a key constituent in perovskite solar cells (PSCs). It should provide efficient and selective electron extraction, low resistivity and high stability. Here, zinc stannate (Zn2SnO4, ZSO) is employed as an ETL in planar ...

Elsevier2020

Benzylammonium‐Mediated Formamidinium Lead Iodide Perovskite Phase Stabilization for Photovoltaics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Dominik Józef Kubicki, David Lyndon Emsley, Zaiwei Wang, Anwar Qasem M Alanazi, Jovana Milic, Dan Ren, Masaud Hassan S Almalki, Aditya Mishra, Felix Thomas Eickemeyer, Hong Zhang

There is an ongoing surge of interest in the use of formamidinium (FA) lead iodide perovskites in photovoltaics due to their exceptional optoelectronic properties. However, thermodynamic instability of the desired cubic perovskite (α-FAPbI3) phase at ambie ...

2021

Engineering ligand reactivity enables high-temperature operation of stable perovskite solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Zaiwei Wang, Felix Thomas Eickemeyer, Mingyang Wei

Perovskite solar cells (PSCs) consisting of interfacial two- and three-dimensional heterostructures that incorporate ammonium ligand intercalation have enabled rapid progress toward the goal of uniting performance with stability. However, as the field cont ...

American Association for the Advancement of Science2023

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

Intermediate phase engineering of halide perovskites for photovoltaics

Ulf Anders Hagfeldt, Zaiwei Wang

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