Publications de Seckin Akin | EPFL Graph Search

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

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

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

Dopant Engineering for Spiro‐OMeTAD Hole‐Transporting Materials towards Efficient Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Jiyoun Seo, Hui-Seon Kim, Jovana Milic, Seckin Akin, Marco Alejandro Ruiz Preciado

One of the most prominent hole-transporting material (HTM) for hybrid perovskite solar cells has been 2,2″,7,7″-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (spiro-OMeTAD), which is commonly doped with metal bis(trifluoromethylsulfonyl)imide ...

2021

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, Mohammad Mahdi Tavakoli, Seckin Akin, Faranak Sadegh, 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

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, Jiyoun Seo, Yuhang Liu, Seckin Akin, Jiahuan Zhang, Felix Thomas Eickemeyer, Hong Zhang, 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

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

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

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

Cyclopentadithiophene-Based Hole-Transporting Material for Highly Stable Perovskite Solar Cells with Stabilized Efficiencies Approaching 21%

Michael Graetzel, Shaik Mohammed Zakeeruddin, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Michael Bauer, Neha Arora, Ryusuke Uchida, Yuhang Liu, Seckin Akin

There is an urge to develop new hole-transporting materials (HTMs) for perovskite solar cells (PSCs), which can yield comparable power conversion efficiencies (PCEs) yet mitigate the issue of stability associated with the state-of-the-art HTM Spiro-MeOTAD. ...

AMER CHEMICAL SOC2020

Site-selective Synthesis of -[70]PCBM-like Fullerenes: Efficient Application in Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Jiyoun Seo, Seckin Akin

We report on the site-selective synthesis of PCBM-like [70]fullerene site-isomers, where the elusive -site-isomers are, for the first time, the major product in a (cyclo)addition chemical reaction involving [70]fullerene. The reaction involves an straightf ...

WILEY-V C H VERLAG GMBH2019

Power output stabilizing feature in perovskite solar cells at operating condition: Selective contact-dependent charge recombination dynamics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Jiyoun Seo, Hui-Seon Kim, Seckin Akin

Stabilized power output at maximum power point (mpp) has been considered as one of the most reliable parameters as it provides a key performance indicator for perovskite solar cells (PSCs) revealing the operational stability of the photovoltaic device. Her ...

Elsevier Science Bv2019

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

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

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

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, Wanchun Xiang, 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

Ultrahydrophobic 3D/2D fluoroarene bilayer-based water-resistant perovskite solar cells with efficiencies exceeding 22%

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Mohammad Ibrahim Dar, Neha Arora, Linfeng Pan, Ryusuke Uchida, Yuhang Liu, Jovana Milic, Alexander Roland Uhl, Seckin Akin

Preventing the degradation of metal perovskite solar cells (PSCs) by humid air poses a substantial challenge for their future deployment. We introduce here a two-dimensional (2D) A(2)PbI(4) perovskite layer using pentafluoro-phenylethylammonium (FEA) as a ...

2019

New Strategies for Defect Passivation in High-Efficiency Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Neha Arora, Seckin Akin

Lead halide perovskite solar cells now show excellent efficiencies and encouraging levels of stability. Further improvements in performance require better control of the trap states which are considered to be associated with vacancies and defects at crysta ...

WILEY-V C H VERLAG GMBH2019

Novel p-dopant toward highly efficient and stable perovskite solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Marko Stojanovic, Jiyoun Seo, Hui-Seon Kim, Seckin Akin

Li-TFSI is the most common p-dopant for the hole conductor spiro-MeOTAD in the normal structure (n-i-p) of perovskite solar cells (PSCs), which consistently yield the highest power conversion efficiency (PCE) albeit at the risk of lower long-term operation ...

ROYAL SOC CHEMISTRY2018

Hydrothermally processed CuCrO2 nanoparticles as an inorganic hole transporting material for low-cost perovskite solar cells with superior stability

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Yuhang Liu, Seckin Akin

Despite the impressive photovoltaic performances of perovskite solar cells (PSCs) with a power conversion efficiency (PCE) beyond 22%, intensive studies are still required to overcome ongoing issues such as cost, stability, and hysteresis. Here, for the fi ...

Royal Society of Chemistry2018