Publications by Yuhang Liu | EPFL Graph Search

Related publications (40)

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

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

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

SnS Quantum Dots as Hole Transporter of Perovskite Solar Cells

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

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

Organic Ammonium Halide Modulators as Effective Strategy for Enhanced Perovskite Photovoltaic Performance

Michael Graetzel, Ulf Anders Hagfeldt, Yuhang Liu, Lukas Pfeifer, Seckin Akin, Bitao Dong

Despite rapid improvements in efficiency, long-term stability remains a challenge limiting the future up-scaling of perovskite solar cells (PSCs). Although several approaches have been developed to improve the stability of PSCs, applying ammonium passivati ...

WILEY2021

Interface modification to achieve high-efficiency and stable perovskite solar cells

Yuhang Liu, Linfeng Pan, Hongwei Zhu, Zhongjin Shen

The organic-inorganic hybrid perovskite solar cells (PSCs) achieve relatively high power conversion efficiencies (PCEs) over the past few years. However, defects on the surface and at the grain boundaries of the perovskite active layers are critical factor ...

ELSEVIER SCIENCE SA2022

Synergistic Effect of Fluorinated Passivator and Hole Transport Dopant Enables Stable Perovskite Solar Cells with an Efficiency Near 24%

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Felix Thomas Eickemeyer, Yuhang Liu, Linfeng Pan, Hongwei Zhu, Yameng Ren, Olivier Ouellette

Long-term durability is critically important for the commercialization of perovskite solar cells (PSCs). The ionic character of the perovskite and the hydrophilicity of commonly used additives for the hole-transporting layer (HTL), such as lithium bis(trif ...

2021

Electron-Affinity-Triggered Variations on the Optical and Electrical Properties of Dye Molecules Enabling Highly Efficient Dye-Sensitized Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Péter Kalman Péchy, Mohammad Ibrahim Dar, Yuhang Liu, Yiming Cao, Yasemin Saygili, Marko Stojanovic

The synthesis, characterization, and photovoltaic performance of a series of indacenodithiophene (IDT)-based D--A organic dyes with varying electron-accepting units is presented. By control of the electron affinity, perfectly matching energy levels were ac ...

Wiley-VCH Verlag GmbH2018

Low-Cost and Highly Efficient Carbon-Based Perovskite Solar Cells Exhibiting Excellent Long-Term Operational and UV Stability

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Yuhang Liu, Neha Arora, Seckin Akin, Thomas Paul Baumeler, Ryusuke Uchida

Today's perovskite solar cells (PSCs) mostly use components, such as organic hole conductors or noble metal back contacts, that are very expensive or cause degradation of their photovoltaic performance. For future large-scale deployment of PSCs, these comp ...

2019

Low-Cost Dopant Additive-Free Hole-Transporting Material for a Robust Perovskite Solar Cell with Efficiency Exceeding 21%

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Felix Thomas Eickemeyer, Yuhang Liu, Linfeng Pan, Hongwei Zhu, Yameng Ren, Zhongjin Shen

Developing hole-transporting materials (HTMs) with appropriate molecular configuration and charge mobility is important to improve perovskite solar cell (PSC) photovoltaic performance and their feasibility for commercialization. In this work, a novel pyram ...

2021

Radical polymeric p-doping and grain modulation for stable, efficient perovskite solar modules

Michael Graetzel, Shaik Mohammed Zakeeruddin, Felix Thomas Eickemeyer, Yuhang Liu, Brian Irving Carlsen

High-quality perovskite light harvesters and robust organic hole extraction layers are essential for achieving high-performing perovskite solar cells (PSCs). We introduce a phosphonic acid???functionalized fullerene derivative in mixed-cation perovskites a ...

American Association for the Advancement of Science2023

Combined Precursor Engineering and Grain Anchoring Leading to MA-Free, Phase-Pure, and Stable alpha-Formamidinium Lead Iodide Perovskites for Efficient Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Yuhang Liu, Dan Ren, Jing Gao, Linfeng Pan, Carole Graetzel, Anurag Krishna, Hongwei Zhu, Olivier Ouellette

alpha-Formamidinium lead iodide (alpha-FAPbI(3)) is one of the most promising candidate materials for high-efficiency and thermally stable perovskite solar cells (PSCs) owing to its outstanding optoelectrical properties and high thermal stability. However, ...

Wiley-VCH Verlag GmbH2021

Upgrading Spiro-OMeTAD with β-Chloroethylcarbazole to Improve the Stability of Perovskite Solar Cells

Michael Graetzel, Yuhang Liu, Haizhou Lu, Jialin Wang

Spiro-OMeTAD has served as a crucial hole transporting material (HTM) in the advancement of efficient perovskite solar cells (PSCs). However, the diminished thermal stability of lithium-doped Spiro-OMeTAD (Li-Spiro) has been a limiting factor, leading to a ...

AMER CHEMICAL SOC2024

Cu2O photocathodes with band-tail states assisted hole transport for standalone solar water splitting

Michael Graetzel, Ulf Anders Hagfeldt, Kevin Sivula, Liang Yao, Yuhang Liu, Dan Ren, Linfeng Pan

Photoelectrochemical water splitting provides a promising solution for harvesting and storing solar energy. As the best-performing oxide photocathode, the Cu2O photocathode holds the performance rivaling that of many photovoltaic semiconductor-based photoc ...

Nature Research2020

High-Performance Lead-Free Solar Cells Based on Tin-Halide Perovskite Thin Films Functionalized by a Divalent Organic

Michael Graetzel, Shaik Mohammed Zakeeruddin, Felix Thomas Eickemeyer, Yuhang Liu

Tin-based halide perovskite solar cells (PSCs) hold the most promise among lead-free PSCs, but they are plagued with inadequate environmental stability and power-conversion efficiency (PCE). Here we demonstrate that the optimum incorporation of a bulky div ...

2020

Stabilization of Highly Efficient and Stable Phase-Pure FAPbI(3)Perovskite Solar Cells by Molecularly Tailored 2D-Overlayers

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Mohammad Ibrahim Dar, Felix Thomas Eickemeyer, Yuhang Liu, Hong Zhang, Jiyoun Seo, Seckin Akin, Hongwei Zhu

As a result of their attractive optoelectronic properties, metal halide APbI(3)perovskites employing formamidinium (FA(+)) as the A cation are the focus of research. The superior chemical and thermal stability of FA(+)cations makes alpha-FAPbI(3)more suita ...

Wiley-VCH Verlag GmbH2020

Hole transport material, synthesis thereof, and solar cell

Michael Graetzel, Shaik Mohammed Zakeeruddin, Yuhang Liu

The organic small molecule 4,4',4",4"'-(5,5-dimethoxycyclopenta-1,3-diene-1,2,3,4-tetrayl)tetrakis(N,N-bis(4-methoxyhenyl)aniline (CPDA 1), shows electrochemical properties very close to spiro-OMeTAD indicating a high compatibility with PSC systems for its ...

2022

Cyclopentadiene-Based Hole-Transport Material for Cost-Reduced Stabilized Perovskite Solar Cells with Power Conversion Efficiencies Over 23%

Michael Graetzel, Shaik Mohammed Zakeeruddin, Yuhang Liu, Felix Thomas Eickemeyer, Hongwei Zhu, Thomas Paul Baumeler

Hole transport materials (HTM) are an important component in perovskite solar cells (PSC). Despite a multitude of HTMs developed in recent years, only few of them lead to solar cells with efficiencies over 20%. Therefore, it is still a challenge to develop ...

2021

Minimizing the Trade-Off between Photocurrent and Photovoltage in Triple-Cation Mixed-Halide Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Yuhang Liu, Neha Arora, Mojtaba Abdi Jalebi, Seckin Akin, Thomas Paul Baumeler, Ryusuke Uchida

Its lower bandgap makes formamidinium lead iodide (FAPbI(3)) a more suitable candidate for single-junction solar cells than pure methylammonium lead iodide (MAPbI(3)). However, its structural and thermodynamic stability is improved by introducing a signifi ...

2020

Comprehensive control of voltage loss enables 11.7% efficient solid-state dye-sensitized solar cells

Shaik Mohammed Zakeeruddin, Jacques-Edouard Moser, Ulf Anders Hagfeldt, Ladislav Kavan, Jingshan Luo, Chenyi Yi, Yuhang Liu, Yiming Cao, Yasemin Saygili, Heewon Bahng

The relatively large voltage loss (Vloss) in excitonic type solar cells severely limits their power conversion efficiencies (PCEs). Here, we report a comprehensive control of Vloss through efficacious engineering of the sensitizer and redox mediator, makin ...

2018

Efficient and Stable Large Bandgap MAPbBr(3) Perovskite Solar Cell Attaining an Open Circuit Voltage of 1.65 V

Michael Graetzel, Shaik Mohammed Zakeeruddin, David Lyndon Emsley, Felix Thomas Eickemeyer, Yuhang Liu, Jing Gao, Linfeng Pan, Michael Allan Hope, Hongwei Zhu, Thomas Paul Baumeler, Olivier Ouellette, Anwar Qasem M Alanazi

We report on the preparation of MAPbBr(3) perovskite films of high electronic quality by applying a methylamine (MA) vapor treatment and mitigating surface defects using the amphiphilic molecular passivator, neopentylammonium chloride (NPACl). We find that ...

2022

Conformal quantum dot-SnO2 layers as electron transporters for efficient perovskite solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Felix Thomas Eickemeyer, Yuhang Liu, Haizhou Lu, Jaeki Jeong

Improvements to perovskite solar cells (PSCs) have focused on increasing their power conversion efficiency (PCE) and operational stability and maintaining high performance upon scale-up to module sizes. We report that replacing the commonly used mesoporous ...

American Association for the Advancement of Science2022