Who ranked the world\’s first chemist? What are you up to?
Michael Gratzel created a molecular photovoltaic field, he was the first who conceived and implemented based on molecular energy collector sightseeing referral system, so far, the performance of the system may be combined with conventional solar battery comparable to or even exceeds the latter. He is considered the PV field is transferred from the principle of absorption of light through the diode to the molecular level of the hero. He proposed a new revolutionary paradigm cell design, as it is characterized by a three-dimensional mesoscopic connection, instead of a flat p-n structure of a conventional solar cell use. This new prototype PV family are The dye-sensitized solar cell (a DSC), also referred to as \”Professor Grätzel cells\” , which uses the dye molecules, dye or quantum dots as light collector. They bind to the support surface is formed by a set of colloidal nanocrystals a wide band gap semiconductor (such as critical electron capture TiO2 or SnO2 as substrate), thereby achieving highly efficient photovoltaic thin film solar cell. At the same time, power production DSCs for battery replacement, glass and electronic equipment in the industry. In addition, he played a key role in the development recently produced directly from DSC perovskite solar cells (PSCs) in. They improve in 2019 the efficiency of solar energy into electricity to more than 25% , this rapid growth has attracted wide interest in research, published more than 10,000 on this subject in the past seven years thesis. Graetzel solar energy production in the field of fuel is also a leader in solar energy technology is the key to the future of storable renewable energy. His team series connection of two optical systems used to decompose water into hydrogen and oxygen, and the reduction of carbon dioxide to visible light. Graetzel 1645 papers were cited 284,000 times, his h-index is 243 (Web of Science, 2019 Nian September) . Stanford University (Stanford University) recently released a rankings in the 100 000 top scientists in all fields , Graetzel ranked first . Since 1991, on dye-sensitized solar cell related article, Michael Graetzel professor made a number of articles and sub-NatureJournal and Science. Which, Michael Graetzel professor published in 1991 in \”Nature\” article on the dye-sensitized solar cell, so far, the number of citations of up to 30717 times. In recent years, Michael Graetzel Prof. focused on solar cells the perovskite (of PSCs) and the field of solar dyes, hair and sub Nature published a number of articles, Science, JACS Angew, and the like. In this paper, will Michael Graetzel recent years, significant research achievements in the DSC, PSCs, and solar fuels and other fields made, coverage in detail.
DSC (dye-sensitized solar cell)
1 Nature Communications:. 11% efficiency with a copper (II / I) a solid hole transport material dye sensitized solar cell
the solid dye-sensitized solar cell deficiencies existing nanopores is filled, low conductivity, the hole-transporting material to permeate mesoscopic TiO2 holder crystallization problems resulting in poor performance. Based on this, Michael Grätzel teams from Lausanne Federal Institute of Higher reported in the air quality standards, using a mixture [Cu (4,4 \’, 6,6- tetramethyl-2,2\’-bipyridine) 2] (bis (trifluoromethylsulfonyl) imide) 2 and [Cu (4,4 \’, 6,6- tetramethyl-2,2\’-bipyridine) 2] (bis (trifluoromethyl sulfonyl) imide) made of a hole transport material, creating a 11% stable, solid dye-sensitized solar cell. Amorphous copper (II / I) conductors, a rapid jump penetration hole 6.5μm- thick frame mesoscopic titania achieve such high efficiency is crucial. Time using time-resolved laser flash photolysis technique, determines the time constant of the electron injected from the excited sensitizer Y123 inject light into the TiO2 time is 25 ps, and Y123 regeneration Cu (I) is a 3.2 μs. This will facilitate the work based on a transition metal complex as the development of low-cost photovoltaic solid hole conductors. 
Reference: Cao, Y., Saygili, Y., Ummadisingu, A. et al 11% efficiency solid-state dye-sensitized solar cells with copper (II / I) hole transport materials Nat Commun 8, 15390 (2017) Original link:… https: //doi.org/10.1038 / ncomms15390
2 Nature photonics:. dye-sensitized solar cell, the effective power in the ambient light
for efficient operation under indoor lighting conditions of the solar cell has great practical value because it It can be used as power source of portable electronic devices and wireless sensor network or a networked device thereof. Based on this, Michael Grätzel team from the Institute of Technology Lausanne Federal Institute demonstrated a dye-sensitized solar cell (DSC), it can achieve very high power conversion efficiency (PCEs) under ambient light conditions. Researchers optical system combines two sensitizer carefully designed, coded and D35 XYl, and copper complex Cu (II / I) (tmby) as a redox shuttle (tmby, 4,4 \’, 6,6 \’- tetramethyl-2,2\’-bipyridine), and having a high open-circuit voltage of 1.1 V of the light. DSC photocurrent generated reaches the external quantum efficiency of over 90% halfway across the visible region from 400 nm to 650nm, and the irradiation OSRAM 930 warm white fluorescent lamp tubes, 200 and 1000 lux, the reached power output of 15.6 and 88.5 μW cm-2. This means that the energy conversion efficiency up to 28.9%. 
Reference: Freitag, M., Teuscher, J., Saygili, Y. et al Dye-sensitized solar cells for efficient power generation under ambient lighting Nature Photon… 11, 372-378 (2017) Original link: https: //doi.org/10.1038/nphoton.2017.60
3 Nature Chemistry:. Dye-sensitized solar cell by molecular engineering porphyrin sensitizer to achieve efficiencies of 13%
the dye-sensitized solar cell because of its low cost, easy to manufacture and tunable optical properties (such as color and opacity) of widespread concern. Based on this, Michael Grätzel team from the Higher Institute of Technology Lausanne Federal reported molecular engineering porphyrin dyes, encoding SM315, depicts a donor member -π bridge – prototype structure of the receptor, while maximizing compatibility with the electrolyte, and improve light collection performance. Linear response, time dependent density functional theory to improve the light trapping the disturbance of the electronic structure. The SM315 cobalt (II / III) redox shuttle is used in conjunction with high open-circuit voltage obtained VOC (0.91 V) of the dye-sensitized solar cell, short-circuit current density JSC of 18.1 mA cm-2, a fill factor of 0.78, [ 123] The power conversion efficiency as high as 13%. Reference:. Mathew, S., Yella, A., Gao, P. et al Dye-sensitized solar cells with 13% efficiency achieved through the molecular engineering of porphyrin sensitizers Nature Chem 6, 242-. . 247 (2014) original link: https: //doi.org/10.1038/nchem.1861 
4 Science:. sensitized solar cell porphyrin cobalt (II / III) based redox electrolyte than 12 % efficiency iodide / triiodide redox shuttle limits the efficiency of the dye-sensitized solar cell. Based on this, from Lausanne, SwitzerlandHigher Federal Institute of Technology Michael Grätzel team reported mesoscopic solar cell – based incorporates a Co (II / III) three – (bipyridine) redox electrolyte solution with a custom synthesis -π bridged donor – acceptor zinc porphyrin morpholine dye as a sensitizer (designated YD2-o-C8). YD2-o-C8 unique molecular design greatly retard the conduction band of titanium dioxide thin film to the back electron transfer rate interface cobalt oxide media to achieve a close to 1 volt ultra high photoelectric efficiency. Since YD2-o-C8 porphyrins absorb in the visible spectrum of sunlight, it will produce a greater photocurrent. YD2-o-C8 organic dye with another co-sensitizer to further improve the performance of the device under simulated sunlight may achieve a power conversion efficiency of 12.3%.
Reference: Aswani Yella et al, Porphyrin-Sensitized Solar Cells with Cobalt (II / III) -Based Redox Electrolyte Exceed 12. Science 334 (6056), 629-634 description link:.. Https: // science. . sciencemag.org/content/334/6056/629
perovskite solar cells (PSCs)
1 Advanced Materials: stable perovskite solar cell tailored amphiphilic molecule damper efficiency was 23.5%. interface defect passivation is an effective means to achieve efficient and stable perovskite solar cell. However, most molecules modulator to mitigate these drawbacks of poor conductivity is formed aggregates at the interface with the charge collection layer perovskite, hindering the extraction of photogenerated carriers. Based on this, Michael Grätzel team from the Institute of Technology Lausanne Federal Institute describes a rational design of passivating agent –4- t-butyl benzyl ammonium iodide (tBBAI), tert-butyl group by its large spatial repulsion prevents unnecessary polymerization. The results showed that, tBBAI surface extracts could significantly accelerate the perovskite charge so that it enters the metal screw transporter, hinder non-radiative charge carrier compound.
It will PSC power conversion efficiency (PCE) from 20% to 23.5% , the retardation decreased to almost undetectable levels. Is important, tBBAI processing fill factor increased from .75 to .82 very high, which reduces the factor from 1.72 to 1.34 over the consistent, demonstrated inhibition of non-radiative carrier recombination. tert-Butyl further provides a hydrophobic umbrella protective film from ambient humidity perovskite erosion. Accordingly, in a continuous analog sun, of PSCs at maximum power point tracking, at 500-hour sunshine, exhibit good running stability, maintaining more than 95% of the initial PCE. Reference: Hongwei Zhu et al, Tailored Amphiphilic Molecular Mitigators for Stable Perovskite Solar Cells with 23.5% Efficiency Adv Mater 2020, 1907757 description link:…. Https: //doi.org/10.1002/adma.201907757 [ 123] 
2 JACS:. a two-dimensional solid-state 19F nuclear magnetic resonance spectrum revealed the supramolecular modulated by a bifunctional halogen bonded to the solar cell hybrid perovskites
by using a different agent as the perovskite organic mineral additive formulations, attempts have been made to overcome the limitations associated with mixed organic-inorganic perovskite of the solar cell stability. Organic additives function primarily confined to the interaction of hydrogen bonds, and atomic level related to the binding mode remains elusive. Here, Michael Grätzel team from the Institute of Technology Lausanne Federal Institute describes a bifunctional supramolecular modulator, 1,2,4,5-tetrafluoroethylene-3,6-diiodobenzene, which by halogen bond trication dihalo perovskite material surface interactions. The researchers calculated two-dimensional solid-state NMR spectroscopy combined with density functional theory to clarify its binding mode. ProvePerovskite solar cell stability supramolecular modulation enhanced, without affecting the photovoltaic performance. Reference: Marco A. Ruiz-Preciado et al, Supramolecular Modulation of Hybrid Perovskite Solar Cells via Bifunctional Halogen Bonding Revealed by Two-Dimensional 19F Solid-State NMR Spectroscopy J. Am Chem Soc 2020, 142….. , 3, 1645-1654 link description: https: //doi.org/10.1021/jacs.9b13701
3 Science:. use efficiency thermodynamic stable β-CsPbI3 perovskite solar cells> 18% [ 123]
Although there is a β-CsPbI3 conducive series bandgap solar cell applications, but is deposited from a stable β-CsPbI3 experimentally it remains a challenge. Here again, Michael Grätzel team from the Institute of Technology Lausanne Federal Institute of high crystallinity is obtained a film having a β-CsPbI3 extended spectral response and enhanced phase stability. Synchrotron X-ray scattering revealed the presence of β-CsPbI3 highly oriented particles, sensitive elemental analysis – including inductively coupled plasma mass and time of flight secondary ion mass spectrometry – confirmed their full inorganic composition. Choline iodine by surface treatment, to further reduce the effects of cracks and pinholes of the perovskite layer, increasing the charge – carrier lifetime, improved β-CsPbI3 absorbing layer and the energy level of the carrier selection between the contact quasi. Perovskite solar cells made from the treated material, at ambient conditions of 45 ± 5 ℃, with high reproducibility and stable efficiency of 18.4%. Reference: Yong Wang et al, Thermodynamically stabilized β-CsPbI3-bas.ed perovskite solar cells with efficiencies> 18% Science, 09 Aug 2019; Vol 365, Issue 6453, pp 591-595 description link:… https: //science.sciencemag.org/content/365/6453/591 [. 123] 4 Nature Materials:. a halide ion conductive perovskite large-scale effect and significance of dimmable light decomposition
and the electron transport is equally important in information technology, ion transport It is a key phenomenon of energy research. Use light to regulate the ionic conductivity for a wide range of new applications and opportunities, but provide clear evidence to this effect has been a challenge. Here, Michael Grätzel team from the Higher Institute of Technology Lausanne Federal by various techniques, such as measuring the number of transfer, permeation studies, the stoichiometry changes, Hall effect and blocking experiments electrode, show that the excitation light can iodide methylene ammonium ion conductivity several orders of magnitude, which is typical of a metal halide photovoltaic material. The researchers provide a theoretical basis for this unexpected phenomenon, and to prove that it directly led to the decomposition of the light path perovskite hitherto not considered.
Reference:… Kim, GY, Senocrate, A., Yang, T. et al Large tunable photoeffect on ion conduction in halide perovskites and implications for photodecomposition Nature Mater 17, 445-449 (2018) Original link: https://doi.org/10.1038/s41563-018-0038-05 Science:. perovskite solar cell production CuSCN hole extraction layer having a stableEfficiency greater than 20%
Currently, solar cells the perovskite (of PSCs) efficiencies of over 20% only use expensive organic hole transporting material can be achieved. Thus, Michael Grätzel team from the Institute of Technology Lausanne Federal Institute proved copper thiocyanate (of CuSCN) holes layer was extracted PSCs, which is stable over 20% efficiency. A rapid method of removing the solvent such that the compact, CuSCN create highly conformal layer, for fast carrier extracted and collected. PSCs exhibits high thermal stability under long term heat, but its poor operational stability. This potential instability is due to degradation caused CuSCN / Au contact. Adding a conductive layer is reduced graphene oxide spacer layer between the gold and CuSCN, allowing PSCs at full solar intensity of 60 deg.] C, the maximum power point after aging at 1000 hours, still maintaining the initial efficiency of> 95%. Under continuous full sun and thermal stress conditions, devices based CuSCN than PSCs based on the stability of the spiro-OMeTAD.
Reference: Neha Arora, Perovskite solar cells with CuSCN hole extraction layers yield stabilized efficiencies greater than 20% Science 358 (6364), 768-771 description link:.. Https: //science.sciencemag.org/content/ . 358/6364/768 solar fuel (solar fuels)
1 Nature Catalysis: Cu2O improving photoelectric properties of the positive electrode for non-aqueous secondary solar decomposition apparatus Although in the past few decades, a lot of research dedicated to splitting photoelectrochemical (PEC) water, but the lack of efficient, stable and rich resources of the earth electrode is still the bottleneck of optoelectronic its practical application. At this point, Michael Grätzel team from the Ecole Polytechnique Federale de Lausanne, Switzerland reported a toolPhotocathode coaxial nanowire structures, which implements Cu2O / Ga2O3- buried p-n junction, more than 600 nanometers effectively collected across the entire visible light region, to achieve external quantum yield close to 80% of hydrogen. Compared with the reversible hydrogen electrode, the electrode having a photocurrent than +1 V, the photocurrent density is at 0 V due to ~ 10mA cm-2, the electrodes constitute the best presently known catalytic generation of hydrogen from the sun Optical oxide cathode. By atomic layer deposition a conformal coating TiO2 protective layer, so that stable running for more than 100 h. NiMo catalyst in a hydrogen evolution, stable operation in a weakly alkaline electrolyte, global access to a wealth of Cu2O content photoelectric cathode. In order to illustrate the actual impact of the photo cathode, the researchers constructed with the most advanced optical BiVO4 negative electrode, a non-series arrangement to build a full oxidation of the solar assisted decomposition of water, about 3% to achieve a sun – hydrogen conversion efficiency. References: Pan, L., Kim, JH, Mayer, MT et al Boosting the performance of Cu2O photocathodes for unassisted solar water splitting devices Nat Catal 1, 412-420 (2018) Original link:… Https: // doi .org / 10.1038 / s41929-018-0077-6
2 Joule:. perovskite / silicon tandem cells and Pt nanoclusters TiC electrocatalyst support for a solar water separator
[123 ] development of efficient, stable and economical optical system, using sunlight to split water into hydrogen and oxygen, the use of resources for the future production of fuels and chemicals essential renewable. However, the high cost of the current system limits their widespread use. Here, Michael Grätzel team from the Institute of Technology Lausanne Federal Institute developed an efficient catalyst of Pt nanoclusters TiC support for the hydrogen evolution reaction, comparable with the commercial Pt / C catalyst, and the Pt load is reduced 5 times . Oxygen binding NiFe- layer hydrochlorothiazide evolution reaction, for the first time by a single perovskite / silicon solar cellSeries, to achieve a decomposition of the solar water system,
Solar achieved – hydrogen conversion efficiency of 18.7%, to create the rich resources of the earth and inexpensive light collector recording water-splitting system.
