1. Current Research Bioelectronics Hybrid molecular/non-molecular, organic/inorganic Materials & Interfaces ALTERNATIVE ENERGY David Cahen 11/’12

2. Current Research Bioelectronics: Proteins as (Opto)Electronic Materials? Proteins as Organic NPs/core-shell QDs “Doping” Proteins Hybrid molecular/non-molecular, organic/inorganic Materials & Interfaces * Remaking Silicon and other Semicond. ALTERNATIVE ENERGY Chemistry & Physics of Light  Electrical Energy conversion * High voltage Solar Cells David Cahen 11/’12

3. Research topics Motivation Understanding & Curiosity (“Everest” research) Help Meet Energy Challenge Blend Electronics with Biology QUESTIONS: (How) can organic molecules change electronics (also with Kronik) ? (How) can proteins be electronic materials (with M. Sheves) ? Why doesn’t nature use electronic conduction ? What are the real limits to efficiency x lifetime) /cost of photovoltaic solar energy conversion? (with G. Hodes) (How) can we make Solar Paint? David Cahen *12/’11

4. Solar Cell Concepts and Materials Basic science towards improving (efficiency x lifetime) /cost of (any) solar cell what are the real limits to PV energy conversion ? Metal-Insulator-Semiconductor solar cells : re-discovering Si Mesoporous, nanocrystalline solid junctions   high voltage solar cells (with G. Hodes)

5. CdS CdTe Adsorbed molecule Adsorption at the PV junction - affects V OC ! ! ! Effects of molecule adsorption on solar cell performance Glass Conductive oxide Poly-xtline p-CdTe h Poly-xtline n-CdS V Back contact Solar Cell Concepts and Materials Molecules as “door-men” HOW IS THIS POSSIBLE ?

6. idealized cartoon SC Pinholes Molecules … because … of physics of dipole layers !

7. Even poorly organized monolayers can do, but need at least average orientation i.e., we can use even discontinuous incomplete monolayers idealized cartoon … because … of physics of dipole layers !

8. ACCEPTORDONOR Device Outline +-+- +-+- +l+l +l+l +l+l +l+l +l+l +l+l  Voc Monolayer: Trimethoxy Silane ~1 nm Metal Contact ~10 nm Metal Contact Donor : Organic Light Absorber ~40 nm R R R R R R R R R R R R R R R R R l l l l l l l l l use or R = Dipole-forming Molecules with M. Bendikov, L. Kronik, R. Naaman A. Kahn (Princeton)

9. Which types of electronic conductors do we know ? Silicon Carbon Nanotubes Heme β-Carotene Pentacene Cu metals semiconductors Diamond Carbon Organic (semi)conductors Bio-molecules? INORGANIC ORGANIC

10. Electronics with Bio-Molecules? Electronic Conduction through Proteins & Peptides What controls transport? High quality device structures Transport (yield, reproducibility) Spectroscopy electronic, electrical optical +++ Theory Electron Transfer Models Electronic structure Transport mechanisms

11. +50 mV Au Lift off float on (LOFO) - Gold 0.2mm 2 10 9 proteins/contact Top Electrode Hg drop or “ready-made Au pad” Hanging Hg drop

12. Cartoon!! Protein Studies at single/few molecules level A 10 nm Metallic substrate 2 μm 2 μm (more) realistic  So … use MACROscopic protein monolayers

13. ….. contact ….. intimate 5 µm 2 contact to a 0.5 nm 2 /molecule monolayer ? contact each grass leaf (~3 cm 2 ) on 70×100 m 2 soccer field [Akkerman] but … still, higher over-all currents  large measuring ability gain Is also a Cartoon!!

14. I-V characteristics protein layers Conducting substrate Linker layer Electrical top contact Protein monolayer Conducting substrate contact

15. HSA vs. BSA Doping Proteins 3.5 nm 4.4 nm

16. HSA-hemin vs. Cyt C 85 meV 90 meV Doping Proteins

17. Temp. independent Thermally activated Electron Transport Mechanisms (bR) Sepunaru et al., JACS 2012

18. OPEN QUESTIONS What are the basic solar light  electricity limits? Needed for better cells / solar paint / high Voltage cells  Tailor solar cells with molecules The inorganic / organic, non-molecular / molecular interface, the next frontier for electronics? (How) can we use proteins as Bioelectronics building blocks? Why is Electron Transport across proteins so efficient ?  Study Peptides  Use also CP-AFM and Electrochemistry  Study biological function effects (e.g., CO/O 2 on myoglobin)  Make new composite materials using protein / NP analogy FURTHER collaboration in WIS with: R. Naaman, I. Lubomirsky, S.Cohen, H.Cohen, D. Oron in Israel with Technion, Bar Ilan U, Tel Aviv U outside Israel with Princeton, Wageningen, UNSW, UT Dallas, NREL, U. Cyprus, Chiba U…...