1. Lesson 4: The physics of low-dimensional semiconductors

2. A) Basic properties of 2D semiconductor nanostructures Quantum well for electrons Thin film of a pure or composed material Heterostructure Common physics

4. a)Band Engineering b)Thickness Engineering Heterostructure (MBE) AlGaAs GaAs - Interband processes - Intraband processes E(z) engineering (modulation)

5. Superlattice Electronic transport???

6. V Electric Field Applied Or Magnetic Field Applied Electronic transport occurs determined by: A)A new band diagram (modified by the electric or magnetic field) B)Electronic density of states C)Tunnelling phenomena D)Temperature E)Electroniuc coupling F)Scattering phenomena

7. kT a<<l e kT<<ΔE

9. Interband Transitions

10. Density of electronic states in a quantum well 3D2D

12. A1) Parabolic and triangular quantum wells - Parabolic well

14. - Triangular well

15. V

16. V=0 V0V0

18. A.2) Superlattices

19. - Kronig-Penney model of a superlattices

20. Minibands Minigaps

21. A3) Modulation-doped heterojunctions

22. A4) MOSFET structures 2D Electron Gas

23. B) Quantum wires (1D semiconductor nanostructures) C Nanotubes Si, Ge nanowires

24. V Electronic transport occurs determined by: A)A new band diagram (modified by the electric or magnetic field) B)Electronic density of states C)Tunnelling phenomena D)Temperature E)Electroniuc coupling F)Scattering phenomena

27. Density of electronic states in a quantum wire

29. C) Quantum dots (0D semiconductor nanostructures)

30. Current???

31. Charging energy (ionization energy) E C (e 2 /C) and single electron effects

32. ΔE E C kT 3D: ΔE>>E C 2D: ΔE>>E C 1D: ΔE>>E C 0D: ΔE~E C 3D, 2D, 1D0D ΔEΔE kT ECEC ΔEΔE ECEC

33. Density of electronic states in a quantum dots