Publications by Likai Zheng | EPFL Graph Search

Spiro-Phenothiazine Hole-Transporting Materials: Unlocking Stability and Scalability in Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Likai Zheng, Jaeki Jeong

Improving both the efficiency and long-term stability of perovskite solar cells (PSCs) is critical for their commercial deployment. Despite the widespread use of spiro-OMeTAD as a hole-transporting material (HTM), its inhomogeneous doping behavior and susc ...

2025

Unraveling the Role of Electron-Withdrawing Molecules for Highly Efficient and Stable Perovskite Photovoltaics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Likai Zheng, Mingyang Wei

Electron-withdrawing molecules (EWMs) have exhibited remarkable efficacy in boosting the performance of perovskite solar cells (PSCs). However, the underneath mechanisms governing their positive attributes remain inadequately understood. Herein, we conduct ...

Wiley-VCH Verlag GmbH2025

Realizing Uniform Defect Passivation via Self‐Polymerization of Benzenesulfonate Molecules in Perovskite Photovoltaics

Michael Graetzel, Xiaoqing Jiang, Likai Zheng, Mingyang Wei

Realizing high‐quality perovskite films through uniform defect passivation and crystallization control is pivotal to unlocking the potential of scalable applications. However, prevalent small‐molecule additives are inherently susceptible to the crystalliza ...

Wiley2025

Suppressing wide-angle light loss and non-radiative recombination for efficient perovskite solar cells

Michael Graetzel, Jing Gao, Likai Zheng

Surface reflections and non-radiative recombinations create energy losses in perovskite solar cells (PSCs) by hindering the generation and extraction of carriers. These losses can reduce device efficiency in practical applications as the incident angle of ...

Nature Publishing Group2025

Dissolvable molecular bridges promoting buried interface modification for high-performance inverted perovskite solar cells

Likai Zheng

Non-radiative recombination and suboptimal interfacial contact at the hole transportation layer (HTL)/perovskite interface critically suppress the device performance and stability of inverted perovskite solar cells (PSCs). Herein, we proposed a dissolvable ...

2025

Low-temperature thermite reaction to form oxygen vacancies in metal-oxide semiconductors: A case study of photoelectrochemical cells

Michael Graetzel, Kevin Sivula, Likai Zheng

The formation of oxygen vacancies (Vö) in n-type semiconductors is a key strategy for improving the performance of metal-oxide-based photoanodes. Whereas Vö has traditionally been created by gas- or liquid-phase treatments, here we report a solid-state red ...

2025

Dopamine Dopes the Performance of Perovskite Solar Cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Shaik Mohammed Zakeeruddin, David Lyndon Emsley, Ursula Röthlisberger, Felix Thomas Eickemeyer, Lukas Pfeifer, Virginia Carnevali, Nikolaos Lempesis

The electron transport layer (ETL) is a crucial component of perovskite solar cells (PSCs) as it greatly influences their photovoltaic performance. Among various currently used ETL materials, SnO₂ stands out due to its unique advantages, including low‐temp ...

Wiley2025

Strain-induced rubidium incorporation into wide-bandgap perovskites reduces photovoltage loss

Michael Graetzel, Shaik Mohammed Zakeeruddin, David Lyndon Emsley, Ursula Röthlisberger, Mounir Driss Mensi, Felix Thomas Eickemeyer, Pascal Alexander Schouwink, Lukas Pfeifer, Jing Gao, Virginia Carnevali

A-site cation mixing can enhance the photovoltaic performance of a wide-bandgap (WBG) perovskite, but rubidium (Rb) cation mixing generally forms a nonperovskite phase. We report that lattice strain locks Rb ions into the α-phase of the lattice of a triple ...

American Association for the Advancement of Science (AAAS)2025

Dipolar Carbazole Ammonium for Broadened Electric Field Distribution in High-Performance Perovskite Solar Cells

Felix Thomas Eickemeyer, Likai Zheng, Jaeki Jeong

Perovskite solar cells (PSCs) with ammonium passivation exhibit superior device performance and stability. Beyond typical chemical passivation, ammonium salts control the electronic structure of perovskite surfaces, yet the molecular structure-property rel ...

2025

All-SnO2-Based Conformal Electron Transport Layer for Efficient Perovskite Solar Cells

Likai Zheng

The fabrication of high-performance perovskite solar cells on high-haze fluorine-doped tin oxide (FTO) substrates with superior light-trapping capabilities necessitates a highly conformal electron transport layer at the bottom interface. Herein, a conforma ...

2024