Publications by Yonghui Lee | EPFL Graph Search

Related publications (39)

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

Ionic polarization-induced current–voltage hysteresis in CH3NH3PbX3 perovskite solar cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Thomas Moehl, Peng Gao, Peng Gao, Yonghui Lee, Simone Meloni, Wolfgang Richard Tress, Marius Franckevicius, Michael Saliba

CH3NH3PbX3 (MAPbX(3)) perovskites have attracted considerable attention as absorber materials for solar light harvesting, reaching solar to power conversion efficiencies above 20%. In spite of the rapid evolution of the efficiencies, the understanding of b ...

Nature Research2016

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

Optoelectronic Properties of Layered Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Yonghui Lee, Tom Theodorus Antonius Lummen, Kyung Taek Cho, Alexandre Vincent Laurent Chenu, 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

PbI2–HMPA Complex Pretreatment for Highly Reproducible and Efficient CH3NH3PbI3 Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Quentin Thomas Jeangros, Emad Oveisi, Peng Gao, Peng Gao, Yonghui Lee, Sanghyun Paek, Giulia Grancini, Yi Zhang

Interfacial engineering of the meso-TiO2 surface through a modified sequential deposition procedure involving a novel PbI2–HMPA complex pretreatment is conducted as a reproducible method for preparing MAPbI3 based perovskite solar cells providing the highe ...

2016

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

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

Mohammad Khaja Nazeeruddin, Yonghui Lee

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

Toward Interaction of Sensitizer and Functional Moieties in Hole-Transporting Materials for Efficient Semiconductor-Sensitized Solar Cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Yonghui Lee

Sb2S3-sensitized mesoporous-TiO2 solar cells using several conjugated polymers as hole-transporting materials (HTMs) are fabricated. We found that the cell performance was strongly cc rrelated with the chemical interaction at the interface of Sb2S3 as sens ...

American Chemical Society2011

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, Alexandre Vincent Laurent Chenu, Florian Berczy, Yi Zhang, Paolo Francioli, Hiroyuki Kanda

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

Targeting Ideal Dual-Absorber Tandem Water Splitting Using Perovskite Photovoltaics and CuInxGa1-xSe2 Photocathodes

Michael Graetzel, Mohammad Khaja Nazeeruddin, Marcel Roland Schreier, Stanley David Tilley, Yonghui Lee, Matthew Thomas Mayer, Jingshan Luo

Efficient sunlight-driven water splitting devices can be achieved by pairing two absorbers of different optimized bandgaps in an optical tandem design. With tunable absorption ranges and cell voltages, organic-inorganic metal halide perovskite solar cells ...

Wiley-V C H Verlag Gmbh2015

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

Efficient inorganic-organic hybrid heterojunction solar cells containing perovskite compound and polymeric hole conductors

Michael Graetzel, Mohammad Khaja Nazeeruddin, Yonghui Lee

Inorganic-organic hybrid structures have become innovative alternatives for next-generation dye-sensitized solar cells, because they combine the advantages of both systems. Here, we introduce a layered sandwich-type architecture, the core of which comprise ...

Nature Publishing Group2013

Femtosecond Charge-Injection Dynamics at Hybrid Perovskite Interfaces

Mohammad Khaja Nazeeruddin, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Michael Saliba, Giulia Grancini

With a power conversion efficiency (PCE) exceeding 22%, perovskite solar cells (PSCs) have thrilled photovoltaic research. However, the interface behavior is still not understood and is a hot topic of research: different processes occur over a hierarchy of ...

Wiley-Blackwell2017

Perovskite solar cells employing organic charge-transport layers

Michael Graetzel, Mohammad Khaja Nazeeruddin, Aswani Yella, Yonghui Lee

Thin-film photovoltaics play an important role in the quest for clean renewable energy. Recently, methylammonium lead halide perovskites were identified as promising absorbers for solar cells(1). In the three years since, the performance of perovskite-base ...

Nature Publishing Group2014

Deep level trapped defect analysis in CH3NH3PbI3 perovskite solar cells by deep level transient spectroscopy

Mohammad Khaja Nazeeruddin, Yonghui Lee

We report the presence of defects in CH3NH3PbI3, which is one of the main factors that deteriorates the performance of perovskite solar cells. Although the efficiency of the perovskite solar cells has been improved by curing defects using various methods, ...

Royal Soc Chemistry2017

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

Highly efficient perovskite solar cells with a compositionally engineered perovskite/hole transporting material interface

Mohammad Khaja Nazeeruddin, Peng Gao, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Cristina Roldán Carmona, Giulia Grancini

Perovskite solar cells (PSCs) have experienced an outstanding advance in power conversion efficiency (PCE) by optimizing the perovskite layer morphol., compn., interfaces, and charge collection efficiency. To enhance PCE, here we developed a new method i.e ...

Royal Soc Chemistry2017