Publications de Yuhang Liu | EPFL Graph Search

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

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

Revealing fundamentals of charge extraction in photovoltaic devices through potentiostatic photoluminescence imaging

Michael Graetzel, Shaik Mohammed Zakeeruddin, Yuhang Liu, Dmitry Bogachuk

The photocurrent density-voltage (J(V)) curve is the fundamental characteristic to assess opto-electronic devices, in particular solar cells. However, it only yields information on the performance inte-grated over the entire active device area. Here, a met ...

ELSEVIER2022

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

Solar reduction of carbon dioxide on copper-tin electrocatalysts with energy conversion efficiency near 20%

Michael Graetzel, Shaik Mohammed Zakeeruddin, Jing Gao, Meng Xia, Yuhang Liu, Dan Ren, Jun Li

Solar-driven carbon dioxide reduction has witnessed a renaissance in the past decades, but the system suffers from low reaction rates. Here the authors develop a copper/tin-oxide electrocatalyst, achieving a new benchmark solar-to-CO energy conversion effi ...

Nature Portfolio2022

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

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

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

Hole transport material, synthesis thereof, and solar cell

Michael Graetzel, Shaik Mohammed Zakeeruddin, Yuhang Liu, Michael Bauer

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

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

Enabling full-scale grain boundary mitigation in polycrystalline perovskite solids

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

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

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, Jing Gao, Thomas Paul Baumeler, Yuhang Liu, Linfeng Pan, Michael Allan Hope, Hongwei Zhu

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