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Peng Gao

Cette personne n’est plus à l’EPFL

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Publications associées (76)

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

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

Molecular engineering of face-on oriented dopant-free hole transporting material for perovskite solar cells with 19% PCE

Mohammad Khaja Nazeeruddin, Paul Gratia, Peng Gao, Kasparas Rakstys, Kyung Taek Cho, Sanghyun Paek, Giulia Grancini

Through judicious molecular engineering, novel dopant-free star-shaped D-pi-A type hole transporting materials coded KR355, KR321, and KR353 were systematically designed, synthesized and characterized. KR321 has been revealed to form a particular face-on o ...

Royal Society of Chemistry2017

Low-Cost Perovskite Solar Cells Employing Dimethoxydiphenylamine-Substituted Bistricyclic Aromatic Enes as Hole Transport Materials

Mohammad Khaja Nazeeruddin, Peng Gao, Kasparas Rakstys, Sanghyun Paek, Giulia Grancini

The synthesis, characterization and photovoltaic performance of series of novel molecular hole transport materials (HTMs) based on bistricyclic aromatic enes (BAEs) are presented. The new derivatives were obtained following a simple and straightforward pro ...

Wiley-V C H Verlag Gmbh2017

Molecularly Engineered Phthalocyanines as Hole-Transporting Materials in Perovskite Solar Cells Reaching Power Conversion Efficiency of 17.5%

Mohammad Khaja Nazeeruddin, Paul Gratia, Peng Gao, Kyung Taek Cho, Cristina Roldán Carmona, Giulia Grancini, Olga Trukhina

Easily accessible tetra-5-hexylthiophene-, tetra-5-hexyl-2,2'-bisthiophene-substituted zinc phthalocyanines (ZnPcs) and tetra-tert-Bu ZnPc are employed as hole-transporting materials in mixed-ion perovskite [HC(NH2)2]0.85(CH3NH3)0.15Pb(I0.8 ...

2017

Dopant-Free Hole-Transporting Materials for Stable and Efficient Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Christian Ludwig, Paul Gratia, Emad Oveisi, Peng Gao, Peng Qin, Kasparas Rakstys, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek

Molecularly engineered novel dopant-free hole-transporting materials for perovskite solar cells (PSCs) combined with mixed-perovskite (FAPbI(3))(0.85)(MAPbBr(3))(0.15) (MA: CH3NH3+, FA: NH=CHNH3+) that exhibit an excellent power conversion efficiency of 18 ...

Wiley-V C H Verlag Gmbh2017

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, 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

Covalent Immobilization of a Molecular Catalyst on Cu2O Photocathodes for CO2 Reduction

Michael Graetzel, Marcel Roland Schreier, Thomas Moehl, Peng Gao, Matthew Thomas Mayer, Jingshan Luo

Sunlight-driven CO2 reduction is a promising way to close the anthropogenic carbon cycle. Integrating light harvester and electrocatalyst functions into a single photo electrode, which converts solar energy and CO2 directly into reduced carbon species, is ...

American Chemical Society2016

Photovoltaic and Amplified Spontaneous Emission Studies of High-Quality Formamidinium Lead Bromide Perovskite Films

Benoît Marie Joseph Deveaud, Mohammad Khaja Nazeeruddin, Thomas Moehl, Mahmoud Saeed Qaid Mohammad Hezam, Peng Gao, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Wolfgang Richard Tress, Neha Arora

This study demonstrates the formation of extremely smooth and uniform formamidinium lead bromide (CH(NH2)(2)PbBr3 = FAPbBr(3)) films using an optimum mixture of dimethyl sulfoxide and N,N-dimethylformamide solvents. Surface morphology and phase purity of t ...

Wiley-Blackwell2016

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

Mohammad Khaja Nazeeruddin, Quentin Thomas Jeangros, Emad Oveisi, 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

Unraveling the Dual Character of Sulfur Atoms on Sensitizers in Dye-Sensitized Solar Cells

Jacques-Edouard Moser, Mohammad Khaja Nazeeruddin, Joël Teuscher, Thomas Moehl, Aswani Yella, Peng Gao, Sadig Aghazada

Cyclometalated ruthenium sensitizers have been synthesized that differ with number of thiophene units on the auxiliary ligands. Sensitizers possessing four (SA25, SA246, and SA285) or none (SA282) sulfur atoms in their structures, were tested in solar cell ...

Amer Chemical Soc2016

Impact of strength and size of donors on the optoelectronic properties of D-pi-A sensitizers

Mohammad Khaja Nazeeruddin, Peng Gao

A series of carbazole based sensitizers with either phenyl based donors (TBC, TMC, OMC, PC, TBR, TMR, OMR and PR) or aryl amine based donors (OMNC, CNC and HNC) as well as one without a donor group (CC) have been synthesized to understand the influence of ...

RSC Publishing2016

Glutathione Modified Gold Nanoparticles for Sensitive Colorimetric Detection of Pb2+ Ions in Rainwater Polluted by Leaking Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Peng Gao, Yaming Yu

In the past few years, the advent of lead halide perovskite solar cells (PSCs) has revolutionized the prospects of the third- generation photovoltaics and the reported power conversion efficiency (PCE) has been updated to 22%. Nevertheless, two main challe ...

American Chemical Society2016

High-Efficiency Perovskite Solar Cells Employing a S,N-Heteropentacene-based D-A Hole-Transport Material

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Peng Gao, Amaresh Mishra, Marius Franckevicius, Dongqin Bi

We developed a new donor--acceptor-type hole-transport material (HTMs) incorporating S,N-heteropentacene as -spacer, triarylamine as donor, and dicyanovinylene as acceptor. In addition to appropriate frontier molecular orbital energies, the new HTM showed ...

Wiley-V C H Verlag Gmbh2016

Enhanced Charge Collection with Passivation Layers in Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Peng Gao, Yonghui Lee, Jingshan Luo, Kyung Taek Cho, Minkyu Son, Jiyoun Seo

The Al2O3 passivation layer is beneficial for mesoporous TiO2-based perovskite solar cells when it is deposited selectively on the compact TiO2 surface. Such a passivation layer suppressing surface recombination can be formed by thermal decomposition of th ...

Wiley-V C H Verlag Gmbh2016

A molecularly engineered hole-transporting material for efficient perovskite solar cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Rosario Scopelliti, Ulf Anders Hagfeldt, Peng Gao, Sadig Aghazada, Juan-Pablo Correa-Baena, Antonio Abate, Taisuke Matsui, Michael Saliba, Filippo de Angelis

Soln.-processable perovskite solar cells have recently achieved certified power conversion efficiencies of over 20%, challenging the long-standing perception that high efficiencies must come at high costs. One major bottleneck for increasing the efficie ...

Nature Publishing Group2016

High-Performance Perovskite Solar Cells with Enhanced Environmental Stability Based on Amphiphile-Modified CH3NH3PbI3

Mohammad Khaja Nazeeruddin, Rosario Scopelliti, Ulf Anders Hagfeldt, Emad Oveisi, Peng Gao, Jingshan Luo, Dongqin Bi

A new aliphatic fluorinated amphiphilic additive is added to CH3NH3PbI3 perovskite to tune the morphology and enhance the environmental stability without sacrificing the performance of the devices. Judicious screening of the perovskite precursor solution r ...

Wiley-V C H Verlag Gmbh2016

A highly hindered bithiophene-functionalized dispiro-oxepine derivative as an efficient hole transporting material for perovskite solar cells

Mohammad Khaja Nazeeruddin, Paul Gratia, Peng Gao, Kasparas Rakstys, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Muhammad Sohail

Dimethoxydiphenylamine-substituted dispiro-oxepine derivative 2,2',7,7'-tetrakis-(N,N'-di-4-methoxyphenylamine)dispiro-[fluorene-9,4'-dithieno(3,2-c:2',3'-e]oxepine-6',9 ''-fluorene] (DDOF) has been designed and synthesized using a facile synthetic route. ...

Royal Society of Chemistry2016

Facile synthesized organic hole transporting material for perovskite solar cell with efficiency of 19.8%

Michael Graetzel, Ulf Anders Hagfeldt, Peng Gao, Dongqin Bi

The exploration of alternative molecular hole-transporting materials (HTMs) specifically for high performance perovskite solar cells (PSCs) is a relatively recent research area. Aiming for further increasing the 'efficiency-cost ratio' of PSCs, we develope ...

Elsevier Science Bv2016

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