Publications de Yonghui Lee | EPFL Graph Search

Enhancement of Piezoelectricity in Dimensionally Engineered Metal-Halide Perovskites Induced by Deep Level Defects

Metal halide perovskite solar cells (PSCs) have been considered to be one of the most promising next-generation energy harvesters over the past decades due to remarkably rapid improvement of power conversion efficiency in photovoltaics. However, energy har ...

WILEY-V C H VERLAG GMBH2022

The Synergism of DMSO and Diethyl Ether for Highly Reproducible and Efficient MA(0.5)FA(0.5)PbI(3)Perovskite Solar Cells

Keith Gregory Brooks, Mohammad Khaja Nazeeruddin, Yonghui Lee, Tom Theodorus Antonius Lummen, Yi Zhang, Hiroyuki Kanda, Ruiyuan Hu, Min Chen

Composition and film quality of perovskite are crucial for the further improvement of perovskite solar cells (PSCs), including efficiency, reproducibility, and stability. Here, it is demonstrated that by simply mixing 50% of formamidinium (FA(+)) into meth ...

2020

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

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

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

Optoelectronic Properties of Layered Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Yonghui Lee, Tom Theodorus Antonius Lummen, Kyung Taek Cho, Sanghyun Paek

Herein, the optoelectronic properties of interface-engineered perovskite 2D|3D-heterojunction structure solar cells are reported. The reciprocity theorem is applied to determine the maximum open-circuit voltage (V-oc) the device can deliver under solar ill ...

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

Inkjet-Printed Mesoporous TiO2 and Perovskite Layers for High Efficiency Perovskite Solar Cells

Hubert Girault, Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Emad Oveisi, Andreas Stephan Lesch, Yonghui Lee, Victor Costa Bassetto, Sanghyun Paek, Aron Joel Huckaba, Rui Xia

Perovskite solar cells with mesoporous TiO2 electron transport layers have previously reached >22 % efficiency at the laboratory scale (

2019

Dimensionally Engineered Perovskite Heterostructure for Photovoltaic and Optoelectronic Applications

Mohammad Khaja Nazeeruddin, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek

Although 2D|3D has shown potential for application in multifunctional devices, the principle of operation for multifunction devices (SOLAR Cell-LED: SOLED) has not yet been revealed. However, most studies have reported that the devices have only one auspic ...

2019

Origins of High Performance and Degradation in the Mixed Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Yonghui Lee

The origins of the high device performance and degradation in the air are the greatest issues for commercialization of perovskite solar cells. Here this study investigates the possible origins of the mixed perovskite cells by monitoring defect states and c ...

Wiley-V C H Verlag Gmbh2019

Efficient Planar Perovskite Solar Cells Using Passivated Tin Oxide as an Electron Transport Layer

Mohammad Khaja Nazeeruddin, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Aron Joel Huckaba, Marco Calizzi

Planar perovskite solar cells using low-temperature atomic layer deposition (ALD) of the SnO2 electron transporting layer (ETL), with excellent electron extraction and hole-blocking ability, offer significant advantages compared with high-temperature depos ...

2018

Inkjet-printed mesoporous TiO2 and perovskite layers for high efficiency perovskite solar cells

Hubert Girault, Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Emad Oveisi, Andreas Stephan Lesch, Yonghui Lee, Victor Costa Bassetto, Sanghyun Paek, Aron Joel Huckaba, Rui Xia

2018

Low-Cost TiS2 as Hole-Transport Material for Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Yonghui Lee, Cristina Roldán Carmona, Aron Joel Huckaba, Giulia Grancini, Saba Gharibzadeh

2018

Influence of Charge Transport Layers on Open-Circuit Voltage and Hysteresis in Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Yonghui Lee, Cristina Roldán Carmona, Giulia Grancini, Saba Gharibzadeh

2018

New Route for "Cold-Passivation" of Defects in Tin-Based Oxides

Christophe Ballif, Aïcha Hessler-Wyser, Quentin Thomas Jeangros, Monica Morales Masis, Yonghui Lee, Federica Landucci, Oscar Esteban Rucavado Leandro

2018

Selective growth of layered perovskites for stable and efficient photovoltaics

Mohammad Khaja Nazeeruddin, Manuel Tschumi, Emad Oveisi, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Giulia Grancini, Pascal Alexander Schouwink

Perovskite solar cells (PSCs) are promising alternatives toward clean energy because of their high-power conversion efficiency (PCE) and low materials and processing cost. However, their poor stability under operation still limits their practical applicati ...

2018

A Facile Preparative Route of Nanoscale Perovskites over Mesoporous Metal Oxide Films and Their Applications to Photosensitizers and Light Emitters

Mohammad Khaja Nazeeruddin, Emad Oveisi, Valentin Ianis Emmanuel Queloz, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Iwan Zimmermann, Aron Joel Huckaba, Giulia Grancini, So-Min Yoo

By two‐step sequential Pb2+ adsorption and reaction with methylammonium‐iodide (MAI) or ‐bromide (MABr) at a low concentration level of 0.06–0.10 m over mesoporous TiO2 or ZrO2 film, a well‐defined nanoscale CH3NH3PbI3 (MAPbI3) photosensitizer or CH3NH3PbB ...

2018

Enhanced charge collection with passivation of the tin oxide layer in planar perovskite solar cells

Mohammad Khaja Nazeeruddin, Robin Humphry-Baker, Emad Oveisi, Peng Gao, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Yi Zhang

Tin oxide is an excellent candidate to replace mesoporous TiO2 electron transport layers (ETLs) in perovskite solar cells. Here, we introduced a SnO2 layer by a low-temperature solution process, and investigated its morphology, opto-physical and electrical ...

Royal Society of Chemistry2017

A Strategy to Produce High Efficiency, High Stability Perovskite Solar Cells Using Functionalized Ionic Liquid-Dopants

Mohammad Khaja Nazeeruddin, Rosario Scopelliti, Paul Joseph Dyson, Zhaofu Fei, Peng Gao, Farzaneh Fadaei Tirani, Yonghui Lee, Yi Zhang

Functionalized imidazolium iodide salts (ionic liquids) modified with -CH2-CH=CH2, -CH2C equivalent to CH, or -CH2C equivalent to N groups are applied as dopants in the synthesis of CH3NH3PbI3-type perovskites together with a fumigation step. Notably, a so ...

Wiley-Blackwell2017

Microscopic Analysis of Inherent Void Passivation in Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Yonghui Lee

The presence of voids in perovskite solar cells influences the efficiency because of accelerated charge recombination. The induced electric field near voids due to band bending attracts photogenerated electrons and holes toward the voids, leading to carrie ...

Amer Chemical Soc2017