Michaël Grätzel

Research summary

Dye- and perovskite-sensitized solar cells are developed across two decades. The ruthenium-bipyridyl charge-transfer sensitizers cis-X2bis(2,2'-bipyridyl-4,4'-dicarboxylate)Ru(II) (X = Cl-, Br-, I-, CN-, SCN-) on nanocrystalline TiO2 electrodes provided the founding sensitizer class for dye-sensitized solar cells [3]. A 1995 review consolidated the photophysics and electrochemistry of nanocrystalline semiconductor films and their solar-conversion behavior [6]. A custom Co(II/III)tris(bipyridyl) redox electrolyte combined with a donor-pi-bridge-acceptor zinc porphyrin sensitizer (YD2-o-C8) retarded interfacial back electron transfer from TiO2 to oxidized cobalt mediator and produced photovoltages approaching 1 V at >12% efficiency, breaking the iodide/triiodide ceiling [4]. Methylammonium lead iodide (CH3NH3PbI3) nanoparticles deposited on mesoporous TiO2 and infiltrated with spiro-MeOTAD produced solid-state heterojunction cells with Jsc >17 mA/cm2, Voc 0.888 V, FF 0.62, and 9.7% PCE, the first highly efficient solid-state perovskite-sensitized device [1]. Femtosecond transient spectroscopy on CH3NH3PbI3 bilayers with selective electron- and hole-extraction layers measured balanced long-range electron-hole diffusion lengths of at least 100 nm, ten times longer than typical solution-processed photovoltaics [2]. Triple cation (Cs/MA/FA) perovskites were shown to be thermally more stable, less impurity-prone, and less processing-sensitive than dual-cation counterparts, yielding stabilized 21.1% PCE that fell to ~18% over 250 h under operating conditions [5]. The work charts the trajectory from Ru-bipyridyl dyes to triple-cation perovskites in solar photovoltaics.

Recent publications

1. A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films1991 · Nature · 28337 citationsDOI
2. Photoelectrochemical cells2001 · Nature · 12560 citationsDOI
3. Sequential deposition as a route to high-performance perovskite-sensitized solar cells2013 · Nature · 9412 citationsDOI
4. Lead Iodide Perovskite Sensitized All-Solid-State Submicron Thin Film Mesoscopic Solar Cell with Efficiency Exceeding 9%2012 · Scientific Reports · 7935 citationsDOI
5. Long-Range Balanced Electron- and Hole-Transport Lengths in Organic-Inorganic CH 3 NH 3 PbI 32013 · Science · 6735 citationsDOI
6. Conversion of light to electricity by cis-X2bis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium(II) charge-transfer sensitizers (X = Cl-, Br-, I-, CN-, and SCN-) on nanocrystalline titanium dioxide electrodes1993 · Journal of the American Chemical Society · 5995 citationsDOI
7. Porphyrin-Sensitized Solar Cells with Cobalt (II/III)–Based Redox Electrolyte Exceed 12 Percent Efficiency2011 · Science · 5948 citationsDOI
8. Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency2016 · Energy & Environmental Science · 5324 citationsDOI
9. Light-Induced Redox Reactions in Nanocrystalline Systems1995 · Chemical Reviews · 5323 citationsDOI
10. Dye-sensitized solar cells with 13% efficiency achieved through the molecular engineering of porphyrin sensitizers2014 · Nature Chemistry · 4394 citationsDOI

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Email Michaël Grätzel 6-12 months before your application deadline. Read several recent papers and reference specific work in your message. Use our how to email a Japanese professor guide for the proven email structure.

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External profiles

• ORCID: https://orcid.org/0000-0002-0068-0195
• OpenAlex: openalex.org

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