La Química y la alta tecnología. Materiales inteligentes

Transcripción

1 Nazario Martín Departamento de Química Orgánica. Facultad de Ciencias Químicas Universidad Complutense de Madrid La Química y la alta tecnología. Materiales inteligentes Los avances de la química y su impacto en la sociedad CSIC, Madrid 25 de marzo de 2009

2 IUPAC name of [60]Fullerene Hentriacontacycle [ ,14.0 3,12.0 4,59.0 5,10.0 6,59.0 7,55.0 8, , , , , , , , , , , , , , , , , , , , , , ,46 ]hexaconta-1,3,5(10),6,8,11,13(18),14,16, 19,21,23,25,27,29(45),30,32(44),33,35(43),36,38(54),39(51),40(48),41,46,49,52,55, 57,59-triacontaene [5,6]-Fullerene-60-I h The fascinating forms of carbon C 60 C 240 C 540 Graphite Diamond Fullerenes (1985) Multiwall carbon Nanotubes (MWNTs; 1991) Graphenes Singlewall carbon Nanotubes (SWNTs; 1993) J. Mater. Chem. 2008, 18, Special issue on Carbon Nanostructu

3 The fascinating forms of carbon Carbon nanoonions Nanohorns Peapod s C nm The Nanoforms of Carbon J. Mater. Chem. 2008, 18, The fascinating forms of carbon Nanocups Nanotorus Nanobuds J. Mater. Chem. 2008, 18,

4 Theme issue: Carbon Nanostructures J. Mater. Chem. 2008, 18, Producción de Fullerenos Vaporización con láser y expansión supersónica Descarga de arco eléctrico en atmósfera inerte Síntesis de Fullerenos en combustiones Fullerenos formados naturalmente

5 Qué propiedades tienen los fullerenos? Fullerenes: Superbencenos o superpolienos?

6 Isolated Pentagon Rule Aromaticidad en el Benceno 1.40 Å

7 Propiedades físicas del C Å (5-6) 1.37 Å (6-6) ΔHº f = 545 Kcal/mol ρ = 1.78 g/cc χ = -260 cgs ppm Sublima por encima de 500 ºC a 10-7 torr Alternancia de enlaces: 1.37 y 1.45 Å The beginning (Resembling the attitude of a scientist in front of the new Fullerene ball) Today (A good control on the basic concepts)

8 Size 100 millions 100 millions d ~ 1 nm An appropriate molecule for the development of nanoscience and nanotechnology but still looking for real applications Size 100 millions Photovoltaics represents one of the most realistic applications of Fullerenes!!! 100 millions d ~ 1 nm An appropriate molecule for the development of nanoscience and nanotechnology but still looking for real applications

9 Renewable Energies Renewable Energies National Geographic, June, 2004

10 Renewable Energies Biomass Eolic energy Hydroelectric energy Solar energy Geothermal energy Solar Map

11 Photosynthesis H 2 O Energy and H OH H HO O HO H H OH H OH electron transfer Luz CO O 2 2 H 2 O Energy and Photosynthesis H OH H HO O HO H H OH OH electron transfer H Mimicking Luz photosynthesis CO we we can: can: O 2 2 Harvesting solar energy Transform it it into into chemical or or electrical power Problems such as as lack lack of of energy, water, foods, environment etc etc could be be solved...

12 Photoinduced Electron Transfer (PET) e + Donor Acceptor 100% Quantum yield ARTIFICIAL PHOTOSYNTHETIC SYSTEMS Las molécula imitan el proceso de la Fotosíntesis. Transferencia electrónica fotoinducida Estado excitado E hν e - D * A D + A - hν Estado de separación de cargas D A

13 d) Bulk heterojunction. Conducting polymers Types of organic solar cells (II) Al ITO Plastic foil OR Alkoxy-PPV Cyano-PPV RO n e- h+ CN n Fabrication of PV devices (I) a) Three layers b) Four layers Al Al D / A material Plastic foil ITO D / A material PEDOT-PSS Plastic foil ITO c) Five layers Al LiF D / A material PEDOT-PSS Plastic foil ITO - PEDOT:PSS. Improves the contact in the interface between the active phase and the ITO electrode - LiF. Makes unlikely that recombination of charges happen after charge transfer

14 Plastic Organic Solar Cells OR RO OR e - RO OR RO Ultrafast PET ITO Metallic electrode hν Transparent substrate F. Wudl, A. Heeger et al. Science, 1992 Bulk heterojunction. Conducting polymer as donor and C 60 as acceptor Al ITO Plastic foil OR Alkoxy-PPV Fullerenes RO n e- h+ OMe O PCBM

15 Bulk heterojunction. Conducting polymer as donor and C 60 as acceptor Inorganic PV devices show η of around 30 % Organic PVs show a better mechanic flexibility and lower production costs. η = 2.5 % CO 2Me O O PCBM O O MDMO-PPV n Architecture of an organic solar cell p-n heterounion Transparent by doping and E HOMO ~E HOMO (D) Cathode Ionic interphase(lif) Active phase (D+A) PEDOT-PSS Anode (ITO) Substrate e - h + C. J. Brabec et al. Adv. Funct. Mater 2001, 11, 15; S. Günes et al. Chem. Rev. 2007, 107, 1324 Bulk heterojunction (BHJ)

16 Organic Solar Cells: How does it work? Bulk-Heterojunction Diodes Photon Electronic Transport Hole Transport e- h + Anode Electric Field Cathode Efecto PV en heterounión LUMO LUMO e HOMO ITO donor acceptor HOMO Efecto fotovoltaico en heterounion p-n - Absorción de luz - Formación del excitón y transferencia electrónica - Movilidad de los transportadores de carga

17 Bulk heterojunction. Conducting polymer as donor and C 60 as acceptor Al ITO R Plastic foil S n P3HT e C 6 H 13 O OC 6 H 13 Polythiophene Fullerenes 4c DPM-12 Adv. Funct. Mater. 2005, 15, 1979 Photovoltaic cells from DPM-12: Optimization studies R Material MDMO-PPV:DPM12 (1:4) MDMO-PPV/ PCBM (1:4) J SC [ma cm -2 ] V OC [V] FF η AM 1.5 [%] a e P3HT S n C 6 H 13 O OC 6 H 13 P3HT:DPM-12 (1:4) P3HT:DPM-12 (1:2) P3HT/PCBM (1:2) a at 78 mw/cm2 white light intensity c DPM-12 Energy Conversion Efficiency of 2.3% Adv. Funct. Mater. 2005, 15, 1979

18 The future of organic solar cells? Silicon photovoltaic solar cells

19 The difference between chemists and physicists: "C 60 " "C60" Physicist who works with chemicals, at the end of the day Synthetic chemists at the end of the day

20 En cualquier caso, las moléculas son las protagonistas. Cuando sean consideradas por la sociedad en su justa medida, la química perderá su mala imagen y podrá ser reconocida como una forma más de expresión de la creatividad humana. hν e -