Publications de Michael Graetzel

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Since reaching 20% efficiency, research in perovskite photovoltaics has shifted from a race for efficiency to a race for stability. For efficiency, the standard test conditions set the rules for the race. However, the term 'stability' is used very broadly ...

We have designed and synthesized a new unsymmetrical zinc phthalocyanine based on 'push-pull' and extended pi-conjugation concept, PCH008. The new sensitizer was fully characterized by CHN anlysis, UV-Vis., fluorescence spectroscopies and cyclic voltammetr ...

Tremendous efforts have been made in developing highly selective catalysts for electrochemical CO 2 conversion to formate. However, the rapid deactivation resulting from structural reconstruction and phase transition poses considerable challenges to the sy ...

Charge transport in nanoparticle-based materials underlies many emerging energy-conversion technologies, yet assessing the impact of nanometre-scale structure on charge transport across micrometre-scale distances remains a challenge. Here we develop an app ...

We report a material screening study for phase transitions of multication hybrid halide perovskite films. Two hundred sixty-six films processed with flash infrared annealing were optically and structurally characterized. This data was compiled into a datab ...

The transport and interfacial transfer of electrons in dye-sensitized solar cells utilizing the Co(dbbip)(2) (dbbip = 2,6-bis(l'-butylbenzimidazol-2'-yl)pyridine) redox couple as an alternative to the conventional I-3(-)/l(-) couple have been investigated ...

Despite its central role in photoelectrochemical (PEC) water splitting, the mechanistic pathway of water oxidation on metal oxides remains unresolved, with population-based and Butler–Volmer (BV) models offering distinct views on how surface valence band holes drive the reaction. Here, we bring together these two perspectives by combining operando photoinduced absorption (PIA) spectroscopy with photocurrent analyses on α-Fe2O3 (hematite) photoanodes as a function of light intensity. We find a crossover from

During the past five years, we have developed in our laboratory a new type of solar cell that is based on a photoelectrochemical process. The light absorption is performed by a monolayer of dye (i.e., a Ruthenium complex) that is adsorbed chemically at the surface of a semiconductor (i.e., titanium oxide (TiO2)). When excited by a photon, the dye has the ability to transfer an electron to the semiconductor. The electric field that is inside the material allows extraction of the electron, and the positive ch

Ruthenium-based C106 and organic D131 sensitizers have been judicially chosen for co-sensitization due to their complementary absorption properties and different molecular sizes. Co-sensitization yields a higher light-harvesting efficiency as well as bette ...

Energy band alignments at heterointerfaces play a crucial role in defining the functionality of semiconductor devices, yet the search for material combinations with suitable band alignments remains a challenge for numerous applications. In this work, we de ...

A new fullerene derivative, PC61BNI, was designed and synthesized in which [6,6]-phenyl C-61-butyric acid methyl ester (PC61BM) was modified by replacing the methyl group with 1,8-naphthalimide (NI) to investigate the molecular structure modification effec ...

A chromophore containing a coplanar dihexyl-substituted dithienosilole (CL1) synthesised for use in dye-sensitised solar cells displayed an energy conversion efficiency of 6.90% under AM 1.5 sunlight irradiation. The new sensitiser showed a similar fill fa ...

Hydrogen is considered as the "holy grail" for the energy community. One of the most promising strategies to produce hydrogen is to split water using renewable energy such as solar radiation. The abundance of water and solar energy enables the potential of ...

Developing hole-transporting materials (HTMs) with appropriate molecular configuration and charge mobility is important to improve perovskite solar cell (PSC) photovoltaic performance and their feasibility for commercialization. In this work, a novel pyram ...

Two series of oxide precursors for perovskite-type (La,Ca)Ti(O,N)(3) were prepared by adding Ca2+ to A-site deficient LaTiO3.5 heterogeneously (Ca2+-backfilling) or by substituting Ca2+ for La3+ in stoichiometric LaTiO3.5 homogeneously (Ca2+-substitution). ...

Optical losses in a photoelectrochemical (PEC) cell account for a substantial part of solar-to-hydrogen conversion losses, but limited attention is paid to the detailed investigation of optical losses in PEC cells. In this work, an optical model of combine ...

The adsorption of dopamine onto an anatase TiO2(101) single crystal has been studied using photoemission and NEXAFS techniques Photoemission Jesuits suggest that the dopamine molecule adsorbs on the surface in a bidentate geometry, resulting in the removal ...

Iodine added to iodide-based ionic liquids leads to extraordi- narily efficient charge transport, vastly exceeding that expect- ed for such viscous systems. Using terahertz time-domain spectroscopy, in conjunction with dc conductivity, diffusivity and visc ...

Square planar gold(iii) complexes that contain functionalised bipyridine ligands of general formula [Au(NN)Cl2][PF6] [where NN = 2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine, 4,4'-dimethoxy-2,2'-bipyridine and 4,4'-diamino-2,2'-bipyridine] have been prep ...

Hybrid metal halide perovskites have demonstrated remarkable performances in modern photovoltaics, although their stabilities remain limited. We assess the capacity to advance their properties by relying on interfacial modulators featuring helical chiralit ...

Michael Graetzel

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Performance of perovskite solar cells under simulated temperature-illumination real-world operating conditions

Unsymmetrical extended pi-conjugated zinc phthalocyanine for sensitization of nanocrystalline TiO2 films

Phase-stable indium sulfide achieves an energy conversion efficiency of 14.3% for solar-assisted carbon dioxide reduction to formate

Identifying champion nanostructures for solar water-splitting

Thermodynamic stability screening of IR-photonic processed multication halide perovskite thin films

Transport and Interfacial Transfer of Electrons in Dye-Sensitized Solar Cells Utilizing a Co(dbbip)(2) Redox Shuttle

Observation of transition from rate law to Butler-Volmer controlled water oxidation kinetics on Hematite Photoanodes

Nanocrystalline titanium oxide electrodes for photovoltaic applications

A selective co-sensitization approach to increase photon conversion efficiency and electron lifetime in dye-sensitized solar cells

Band Alignment Engineering at Cu2O/ZnO Heterointerfaces

Design, synthesis and characterization of 1,8-naphthalimide based fullerene derivative as electron transport material for inverted perovskite solar cells

Organic Dyes Containing Coplanar Dihexyl-Substituted Dithienosilole Groups for Efficient Dye-Sensitised Solar Cells

Solar Water Splitting Using Earth-Abundant Electrocatalysts Driven by High-Efficiency Perovskite Solar Cells

Low-Cost Dopant Additive-Free Hole-Transporting Material for a Robust Perovskite Solar Cell with Efficiency Exceeding 21%

Structural and photocatalytic properties of perovskite-type (La,Ca)Ti(O,N)(3) prepared from A-site deficient precursors

Analysis of Optical Losses in a Photoelectrochemical Cell: A Tool for Precise Absorptance Estimation

Dopamine Adsorption on Anatase TiO2(101): A Photoemission and NEXAFS Spectroscopy Study

Extraordinarily efficient conduction in a redox-active ionic liquid

Synthesis, characterisation and biological properties of gold(iii) compounds with modified bipyridine and bipyridylamine ligands

Helical interfacial modulation for perovskite photovoltaics