Publications by Sanghyun Paek | EPFL Graph Search

Green-Chemistry-Inspired Synthesis of Cyclobutane-Based Hole-Selective Materials for Highly Efficient Perovskite Solar Cells and Modules

Mohammad Khaja Nazeeruddin, Kasparas Rakstys, Sanghyun Paek, Yi Zhang, Hiroyuki Kanda

Hybrid lead halide perovskite solar cells (PSCs) have emerged as potential competitors to silicon-based solar cells with an unprecedented increase in power conversion efficiency (PCE), nearing the breakthrough point toward commercialization. However, for h ...

Wiley-VCH Verlag GmbH2022

Cation optimization for burn-in loss-free perovskite solar devices

Mohammad Khaja Nazeeruddin, Tom Theodorus Antonius Lummen, Marius Franckevicius, Sanghyun Paek, Cristina Roldán Carmona, Olga Syzgantseva

Hybrid lead halide perovskites will potentially lead the future energy scenario if highly efficient cells have long-term stability. Here we combine state-of-the art mixed-cation formulations containing formamidinium (FA) and methylammonium (MA), with optim ...

Royal Society of Chemistry2021

Effect of illumination and applied potential on the electrochemical impedance spectra in triple cation (FA/MA/Cs) 3D and 2D/3D perovskite solar cells

Mohammad Khaja Nazeeruddin, Sanghyun Paek, Zubair Ahmad

Even though there has been numerous works performed based on electrochemical impedance spectroscopy (EIS) of perovskite solar cells (PSCs), however, many aspects of the obtained EI spectra are yet to be fully grasped. Moreover, the change of these spectra ...

ELSEVIER SCIENCE SA2021

Consequence of aging at Au/HTM/perovskite interface in triple cation 3D and 2D/3D hybrid perovskite solar cells

Mohammad Khaja Nazeeruddin, Tom Theodorus Antonius Lummen, Sanghyun Paek, Zubair Ahmad

Perovskite solar cells (PSCs) expressed great potentials for offering a feasible alternative to conventional photovoltaic technologies. 2D/3D hybrid PSCs, where a 2D capping layer is used over the 3D film to avoid the instability issues associated with per ...

Nature Research2021

Cation optimization for burn-in loss-free perovskite solar devices (vol 9, pg 5374, 2021)

Mohammad Khaja Nazeeruddin, Sanghyun Paek, Cristina Roldán Carmona

Royal Society of Chemistry2021

Assessing mobile ions contributions to admittance spectra and current-voltage characteristics of 3D and 2D/3D perovskite solar cells

Mohammad Khaja Nazeeruddin, Sanghyun Paek, Zubair Ahmad

Recently, the 2D perovskite layer is employed as a capping/passivating layer in the perovskite solar cells (PSCs). The 2D perovskite layer is prepared by inserting a large-sized hydrophobic cation spacer into the perovskite crystal lattice. The large-sized ...

2020

Elucidating the Doping Mechanism in Fluorene-Dithiophene-Based Hole Selective Layer Employing Ultrahydrophobic Ionic Liquid Dopant

Mohammad Khaja Nazeeruddin, Tom Theodorus Antonius Lummen, Sanghyun Paek, Laura Calio

Perovskite solar cells have set a new milestone in terms of efficiencies in the thin film photovoltaics category. Long-term stability of perovskite solar cells is of paramount importance but remains a challenging task. The lack of perovskite solar cells st ...

2020

D-pi-A-Type Triazatruxene-Based Dopant-Free Hole Transporting Materials for Efficient and Stable Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Kasparas Rakstys, Sanghyun Paek, Cristina Roldán Carmona, Hiroyuki Kanda, Cansu Igci, Hobeom Kim

Three donor-pi-bridge-acceptor (D-pi-A)-type organic small molecules coded CI-B1, CI-B2, and CI-B3 are designed, synthesized, and used as dopant-free hole transporting materials (HTMs) for perovskite solar cells (PSCs). The strong electron-donating triazat ...

WILEY-V C H VERLAG GMBH2020

Carbazole-Terminated Isomeric Hole-Transporting Materials for Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Kasparas Rakstys, Sanghyun Paek, Hiroyuki Kanda

A set of novel hole-transporting materials (HTMs) based on pi-extension through carbazole units was designed and synthesized via a facile synthetic procedure. The impact of isomeric structural linking on their optical, thermal, electrophysical, and photovo ...

AMER CHEMICAL SOC2020

Gradient band structure: high performance perovskite solar cells using poly(bisphenol A anhydride-co-1,3-phenylenediamine)

Mohammad Khaja Nazeeruddin, Sanghyun Paek, Cristina Roldán Carmona, Aron Joel Huckaba, Hiroyuki Kanda, Mousa Abdulla M E Abuhelaiqa, Nadja Isabelle Desiree Klipfel, Albertus Adrian Sutanto, Hobeom Kim, Maria Cristina Momblona Rincón, Ryuji Kaneko

Surface passivation is a critical factor for improving the photovoltaic performance of perovskite solar cells. However, more robust principle investigations are required to build effective passivation strategies enabling high-performance perovskite solar c ...

Royal Society of Chemistry2020

Band-bending induced passivation: high performance and stable perovskite solar cells using a perhydropoly(silazane) precursor

Mohammad Khaja Nazeeruddin, Mounir Driss Mensi, Valentin Ianis Emmanuel Queloz, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Cristina Roldán Carmona, Aron Joel Huckaba, Giulia Grancini, Yi Zhang, Hiroyuki Kanda, Nadja Isabelle Desiree Klipfel, Mo Li

Surface passivation of the perovskite photo absorber is a key factor to improve the photovoltaic performance. So far robust passivation strategies have not yet been revealed. Here, we demonstrate a successful passivation strategy which controls the Fermi-l ...

2020

Detection of voltage pulse width effect on charge accumulation in PSCs EFISHG measurement

Mohammad Khaja Nazeeruddin, Sanghyun Paek, Zubair Ahmad

We report the effect of applied pulse width on charge accumulation in triple cation perovskite solar cells (PSCs) during the Electric Field Induced Second Harmonic Generation (EFISHG) measurements. The PSCs were prepared in the n-i-p structure using the la ...

ELSEVIER2020

Doped but Stable: Spirobisacridine Hole Transporting Materials for Hysteresis-Free and Stable Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Anne-Clémence Corminboeuf, Marius Franckevicius, Sanghyun Paek, Cristina Roldán Carmona, Nikita Drigo, Kun-Han Lin, Pascal Alexander Schouwink, Albertus Adrian Sutanto, Hobeom Kim, Muhammad Sohail

Four spirobisacridine (SBA) hole-transporting materials were synthesized and employed in perovskite solar cells (PSCs). The molecules bear electronically inert alkyl chains of different length and bulkiness, attached to in-plane N atoms of nearly orthogona ...

AMER CHEMICAL SOC2020

Enhanced stability of alpha-phase FAPbI(3) perovskite solar cells by insertion of 2D (PEA)(2)PbI4 nanosheets

Mohammad Khaja Nazeeruddin, Tom Theodorus Antonius Lummen, Sanghyun Paek, Yi Zhang, Ruiyuan Hu

Methylammonium (MA) is one of the main obstacles that hold back the commercialization of perovskite solar cells (PSCs). Formamidinium (FA)-based perovskite is a promising photovoltaic material due to its higher thermal stability and smaller bandgap. Howeve ...

Royal Society of Chemistry2020

Effective Preparation of Nanoscale CH3NH3PbI3 Perovskite Photosensitizers for Mesoporous TiO2-Based Solar Cells by Successive Precursor Layer Adsorption and Reaction Process

Mohammad Khaja Nazeeruddin, Yonghui Lee, Tom Theodorus Antonius Lummen, Kyung Taek Cho, Sanghyun Paek, Iwan Zimmermann, Aron Joel Huckaba, Hobeom Kim, So-Min Yoo

Nanoscale CH3NH3PbI3 perovskite sensitizers are grown by delivering each precursor successively onto the surface of mesoporous (meso) TiO2 electrodes. Using Pb(NO3)(2) ions as a lead(II) source and CH3NH3I (MAI) for methylammonium and iodide sources, repet ...

2020

Self-Crystallized Multifunctional 2D Perovskite for Efficient and Stable Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Aron Joel Huckaba, Albertus Adrian Sutanto, Hobeom Kim

Recently, perovskite solar cells (PSC) with high power-conversion efficiency (PCE) and long-term stability have been achieved by employing 2D perovskite layers on 3D perovskite light absorbers. However, in-depth studies on the material and the interface be ...

WILEY-V C H VERLAG GMBH2020

Molecular Design and Operational Stability: Toward Stable 3D/2D Perovskite Interlayers

Mohammad Khaja Nazeeruddin, Anne-Clémence Corminboeuf, Kyung Taek Cho, Marius Franckevicius, Sanghyun Paek, Cristina Roldán Carmona, Nikita Drigo, Kun-Han Lin, Pascal Alexander Schouwink, Hiroyuki Kanda, Hobeom Kim

Despite organic/inorganic lead halide perovskite solar cells becoming one of the most promising next-generation photovoltaic materials, instability under heat and light soaking remains unsolved. In this work, a highly hydrophobic cation, perfluorobenzylamm ...

2020

Dynamical evolution of the 2D/3D interface: a hidden driver behind perovskite solar cell instability

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Kyung Taek Cho, Sanghyun Paek, Nikita Drigo, Giulia Grancini, Pascal Alexander Schouwink, Inés Garcia Benito, Albertus Adrian Sutanto

Engineering two-/three-dimensional (2D/3D) perovskite solar cells is nowadays a popular strategy for efficient and stable devices. However, the exact function of the 2D/3D interface in controlling the long-term device behavior is still obscure. Here, we re ...

Royal Society of Chemistry2020

Crystal Orientation Drives the Interface Physics at Two/Three-Dimensional Hybrid Perovskites

Jacques-Edouard Moser, Mohammad Khaja Nazeeruddin, Marine Eva Fedora Bouduban, Valentin Ianis Emmanuel Queloz, Kyung Taek Cho, Sanghyun Paek, Cristina Roldán Carmona, Giulia Grancini

Combining halide perovskites with tailored dimensionality into two/three-dimensional (2D/3D) systems has revealed a powerful strategy to boost the performances of perovskite photovoltaics (PVs). Despite recent advances, a clear understanding of the intimat ...

2019

Stable perovskite solar cells using tin acetylacetonate based electron transporting layers

Mohammad Khaja Nazeeruddin, Robin Humphry-Baker, Emad Oveisi, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Aron Joel Huckaba, Yi Zhang, Hiroyuki Kanda, Mousa Abdulla M E Abuhelaiqa, Hobeom Kim

Organic-inorganic lead halide perovskites with over 23% power conversion efficiency have attracted enormous academic and industrial attention due to their low-cost fabrication and high device performance. Self-passivated tin oxide as an electron transport ...

ROYAL SOC CHEMISTRY2019