Intrinsic and extrinsic silicon semiconductors

In summary, the conversation discusses the deliberate doping of a wafer of intrinsic silicon with acceptor atoms and the subsequent calculation of electron and hole concentration, Fermi level position, and conductivity in the wafer. The conversation also mentions the constants and equations needed for the calculations and requests for help with the solution.
  • #1
wonder
1
0
Can some1 please assist me with this question,i have tried every means possible with no avail.
1,
A wafer of intrinsic silicon is deliberately doped with 3 X 10^20/m^-3 of acceptor atoms
1, CAlculate the electron and hole concntration in the wafer
2,calc the position of the Fermi level in the band-gap
3calculate the conductivity of the wafer

Constants
q = 1.6 X 10^-19C,k = 1.38 X 10^-23J/K = 8.6 X 10^-5eV/K,ni = 1.45 X 10^16m-3,Nc= 2.5 X 10^25m^-3,EG(Si)= 1.1eV...
Thanks a lot in advance for your assiatance


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The Attempt at a Solution

 
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1. What is the difference between intrinsic and extrinsic silicon semiconductors?

Intrinsic silicon semiconductors are pure silicon crystals that have no impurities added. They have an equal number of electrons and holes, making them poor conductors at room temperature. Extrinsic silicon semiconductors have impurities added to them, which either introduce extra electrons (n-type) or create holes (p-type) in the crystal structure. This allows for more control over the conductivity of the material.

2. How do intrinsic and extrinsic silicon semiconductors differ in terms of their band structure?

The band structure of intrinsic silicon semiconductors has a band gap between the valence band (where electrons reside) and the conduction band (where electrons can move freely). This gap is narrow, making it easier for electrons to jump from the valence band to the conduction band at higher temperatures. In extrinsic silicon semiconductors, the addition of impurities creates energy levels within the band gap, making it easier for electrons to move around and increasing the conductivity of the material.

3. What is the role of impurities in extrinsic silicon semiconductors?

Impurities, also known as dopants, are added to extrinsic silicon semiconductors to alter their electrical properties. The type of impurity added determines whether the resulting material is n-type or p-type. N-type semiconductors have impurities that introduce extra electrons, while p-type semiconductors have impurities that create holes in the crystal structure. This manipulation of the number of free electrons or holes allows for the creation of more complex electronic devices.

4. How does temperature affect the conductivity of intrinsic and extrinsic silicon semiconductors?

At room temperature, intrinsic silicon semiconductors have a limited number of free electrons, making them poor conductors. However, as the temperature increases, more electrons are able to jump from the valence band to the conduction band, increasing the conductivity of the material. Extrinsic silicon semiconductors, on the other hand, have a higher conductivity at room temperature due to the addition of impurities. As the temperature increases, the number of free electrons also increases, leading to a further increase in conductivity.

5. What are some common applications of intrinsic and extrinsic silicon semiconductors?

Intrinsic and extrinsic silicon semiconductors are the building blocks of modern electronic devices. Intrinsic silicon semiconductors are used in the production of solar cells, sensors, and electronic components such as diodes and transistors. Extrinsic silicon semiconductors, with their higher conductivity, are used in more complex electronic devices like computer chips and microprocessors.

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