1. Module A-4 Molecular Electronics1

2. Bohr Atomic Model

3. Hydrogen Emission Spectra
Principal Quantum Number

4. Principal Quantum Numbers
Orbital Quantum Number
l = 0 to l = (n–1)

5. Quantum Energy States

6. Principal Quantum Numbers

7. Molecular Orbital Considerations
H  H-H  H-H-H  H-H-H-H (1s electrons)
Li  Li-Li  Li-Li-Li  Li-Li-Li-Li (2s electrons)
(Li–Li = 2.67 A, H–H = 0.75 A)

8. Molecular s-Bonding and s* Bonding States

9. s bonds
Electrons in chemical bonds ( e.g. H-H and C-H bonds) are generally quite localized and non-conducting. These bonds are s bonds.

10. Alkyl Chains and Aliphatic molecular Insulators
s-type orbits lie in the molecular plane and are insulating

11. Formulation of Large Molecular Chains

12. Formation of Energy Bands from Constituent Atoms

13. Energy Bands for metals, semiconductors and Insulators

14. Bandgap vs. Chain Length
Poly(thiophene)

15. All properties approach a saturation value.
Saturation Effect
All properties approach a saturation value.

16. Bandgap vs. conjugation length
Increased conjugation length  smaller bandgap

17. Genesis of Nanotechnology
00 Chemistry
96 Chemistry
86 Physics
56 Physics
97 chemistry
Genesis of Nanotechnology
(Mitre 96)

18. Single Electron Transistors

20. Molecular Break junction SET

21. STM in Molecular Electronic Research
Semiconducting