Virtual Labs

1. What is the work function of a material?

a: The energy required to break a covalent bond Explanation

Explanation

b: The energy required to move an electron from the conduction band to the vacuum level Explanation

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c: The bandgap energy of the material Explanation

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d: The energy to create an electron-hole pair Explanation

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2. What is electron affinity in a semiconductor?

a: The energy gap between conduction and valence bands Explanation

Explanation

b: The energy required to excite an electron from the valence to conduction band Explanation

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c: The energy difference between the conduction band and vacuum level Explanation

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d: The energy required to ionize a dopant Explanation

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3. What type of contact is formed when metal work function is less than n-type semiconductor's electron affinity?

a: Schottky contact Explanation

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b: Ohmic contact Explanation

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c: p-n junction Explanation

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d: No contact is formed Explanation

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4. In a Metal-Semiconductor junction with an n-type semiconductor, increasing the forward bias results in:

a: Wider depletion region and lower current Explanation

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b: Smaller barrier height and increased current Explanation

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c: No change in current Explanation

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d: Breakdown of the junction Explanation

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5. What would happen to the energy band diagram of an n-type MS junction under reverse bias?

a: Conduction band bends downward Explanation

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b: Valence band shifts closer to Fermi level Explanation

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c: Conduction band bends upward increasing barrier Explanation

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d: Fermi level moves significantly Explanation

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6. Which factor does **not** directly affect the Schottky barrier height?

a: Metal work function Explanation

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b: Semiconductor electron affinity Explanation

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c: Semiconductor doping concentration Explanation

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d: Semiconductor dielectric constant Explanation

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7. A metal has work function φ_m = 5.1 eV, and the n-type semiconductor has electron affinity χ = 4.0 eV and E_c – E_F = 0.2 eV. What is the Schottky barrier height (φ_Bn)?

a: 1.1 eV Explanation

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b: 0.7 eV Explanation

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c: 2.0 eV Explanation

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d: 5.3 eV Explanation

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8. A metal forms a Schottky junction with a semiconductor. If the temperature increases, how does the reverse saturation current behave?

a: It increases exponentially Explanation

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b: It stays constant Explanation

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c: It decreases linearly Explanation

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d: It becomes zero Explanation

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9. In the MS junction simulation, varying the doping level affects which of the following most significantly?

a: The metal's work function Explanation

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b: The width of the depletion region Explanation

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c: The bandgap of the semiconductor Explanation

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d: The vacuum level Explanation

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Metal-Semiconductor Junctions