Publications de Jaeki Jeong | EPFL Graph Search

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

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

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

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

Felix Thomas Eickemeyer, Jaeki Jeong, Likai Zheng

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

Single junction CsPbBr3 solar cell coupled with electrolyzer for solar water splitting

Michael Graetzel, Shaik Mohammed Zakeeruddin, Jaeki Jeong

Artificial photosynthesis system to realize Solar overall water splitting has been regarded as sustainable and renewable solution for energy and environmental issues. While artificial photosynthesis system (efficiency of 12.4%) greatly exceeds efficiency o ...

2025

Carbazole Treated Waterproof Perovskite Films with Improved Solar Cell Performance

Michael Graetzel, Paul Joseph Dyson, Ursula Röthlisberger, Haizhou Lu, Felix Thomas Eickemeyer, Yeonju Kim, Jaeki Jeong, Lukas Pfeifer, Nikolaos Lempesis, Virginia Carnevali

Surface passivation has been widely employed to suppress non-radiative charge recombination and prevent interfacial charge accumulation in perovskite photovoltaics. In this report, carbazole modified with ammonium iodide connected via alkyl chains of diffe ...

Wiley-V C H Verlag Gmbh2024

Coordination modulated passivation for stable organic-inorganic perovskite solar cells

Ulf Anders Hagfeldt, Yeonju Kim, Jaeki Jeong

Despite the recent exceptional rise in power conversion efficiency of perovskite solar cells (PSCs), surface defects and ion migration related instability are still present in PSCs. The chain length and binding energy of the passivation material play impor ...

2023

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

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

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

Formate as Anti-Oxidation Additives for Pb-Free FASnI(3) Perovskite Solar Cells

Jiyoun Seo, Jaeki Jeong, Jinhyun Kim, Jiwon Kim

Pb-free Sn-based perovskite solar cells (PSCs) have significant potential for application in photovoltaic devices because oftheir suitable bandgap, low exciton binding energy, high carrier mobility, and long diffusion length. However, their performance is ...

WILEY-V C H VERLAG GMBH2022

Modulation of perovskite crystallization processes towards highly efficient and stable perovskite solar cells with MXene quantum dot-modified SnO2

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Yuhang Liu, Tian Chen, Haizhou Lu, Jaeki Jeong

Nanocrystalline tin (iv) oxide (SnO2) electron-transport layers (ETL) have shown great potential for achieving highly efficient, stable perovskite solar cells (PSCs), in particular low-temperature-processed flexible PSCs. Recently, studies have further sho ...

2021

Pseudo-halide anion engineering for α-FAPbI3 perovskite solar cells

Jiyoun Seo, Haizhou Lu, Jaeki Jeong

Metal halide perovskites of the general formula ABX3—where A is a monovalent cation such as caesium, methylammonium or formamidinium; B is divalent lead, tin or germanium; and X is a halide anion—have shown great potential as light harvesters for thin-film ...

2021

Ultrafast carbothermal reduction of silica to silicon using a CO2 laser beam

Jaeki Jeong

We report the extraction of silicon via a carbothermal reduction process using a CO2 laser beam as a heat source. The surface of a mixture of silica and carbon black powder became brown after laser beam irradiation for a few tens of seconds, and clear peak ...

NATURE RESEARCH2020