4. Label the following energy level diagrams using the appropriate type of conduction term (insulator, metal,...
4. Label the following energy level diagrams using the appropriate type of conduction term (insulator, metal, semiconductor).
(2) In a semiconductor with an energy gap Eg between the valence and the conduction bands we can take Ef (the Fermi energy) to be halfway between the bands (see figure below): Conduction band Energy gap Eg Valence band Semiconductor a. Show that for a typical semiconductor or insulator at room temperature the Fermi- Dirac factor is approximately equal to exp(-E 2kBT). (Typical Eg for semi-conductors ranges from about 0.5eV to 6eV at T-293K.) b. In heavily doped n-type silicon,...
4. Label each band diagram below with an appropriate label.(4) Draw the band diagram for a p-type and n-type semiconductor(4). Briefly describe an experiment that you could perform to distinguish between a conductor and a semiconductor (they both look shiny and hard at room temperature).(2) (10 points) (d (rt o :ODH Energy
Which of the following statements concerning semiconductors is/are CORRECT? 1. The conduction of electricity in p-type semiconductors occurs by the movement of electrons in the conduction band. 2. Doping an intrinsic semiconductor, such as silicon, with a Group 3A element will produce a p-type semiconductor. 3. An n-type semiconductor uses the movement of positive holes in the valence band to conduct electricity.
4. A metal and p-type Si (Ds > Фт) are brought together to form Junction. (a) Draw energy band structure for metal and p-type semiconductor? (b) Will the junction be ohmic or Schottky? Why? (c) If the doping in the Si layer is p-1017cm-3. Фт=3eV,猛2.5eV, Ea (Si)|JeV, д-15x100 cm-3, calculate Vin and energy barrier height Фь.? 4. A metal and p-type Si (Ds > Фт) are brought together to form Junction. (a) Draw energy band structure for metal and p-type...
Define the majority carrier concentration in an n-type Si semiconductor in terms of the conduction band edge energy E, and the Fermi energy E. 1. 2 marks Find an expression for Ee -Ef, i.e, the difference between the conduction band edge energy and the Fermi energy in terms of the donor concentration ND. 4 marks Determine the concentration of donor impurity atoms that must be added to silicon so that Ec- E0.2 eV. 3 marks
3. Energy Diagrams: Using the axes below, draw an energy diagram for an endothermic reaction. Label the following in your diagram: The reactants "The products "The activation energy "The total energy gained or lost by the reaction (AH) reaction progress
Question 7 When the conduction electrons in a metal are treated as an ideal gas of fermions, the mean number of electrons occupying a state with energy e is given by I+ (-2) (3)u (a) Define the Fermi energy [ marks] (b) Sketch n as a function of e for an electron gas: (i) at T 0 K, and to the Fermi temperature (ii) at a temperature above 0 K, but small compared Label and briefly justify each sketch [5...
1. Define the majority carrier concentration in an n-type Si semiconductor in terms of the conduction band edge energy Ec and the Fermi energy Ep 2 marks Find an expression for Ec - Ep, i.e, the difference between the conduction band edge energy and the Fermi energy in terms of the donor concentration Np. 4 marks Determine the concentration of donor impurity atoms that must be added to silicon that Ec Ef = 0.2 eV So 4 marks
How many states are in the n = 4 shell? 4 9 16 18 32 If a solid has a half-filled valence band, which of the following would it be? a conductor an insulator a semiconductor a p-type semiconductor an n-type semiconductor If an element has a band gap of 1 eV between a filled valence band and an empty conduction band, it would be classified as a(n) insulator. conductor. resistor. semiconductor. reactor. If the momentum of a particle is...