Relative permittivity of a semiconductor material

In summary, the relative permittivity of a p-type semiconductor material was measured using a M-S-M structure and thermal evaporation method. The measured capacitance at room temperature and 1 kHz frequency was used to calculate the relative permittivity using the equation C=ε_r ε0 A/d. However, the calculated value was significantly lower than 1, leading to the suspicion that the LCR meter used may be defective. Further investigation is needed to determine the validity of the assumption that the M-S-M structure behaves like a parallel plate capacitor and to understand the behavior of the device's I-V characteristic and the interface between the metal and semiconductor.
  • #1
r.sahebi
12
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http://physics.stackexchange.com/questions/156708/can-the-relative-permittivity-of-a-semiconductor-material-be-lower-than-1

To measure the relative permittivity of a p-type semiconductor material (a metal phthalocyanine ) , a M-S-M structure was made by thermal evaporation method. The capacitance was measured by a LCR meter at room temperature under the frequency of 1 kHz and the thickness of semiconductor layer and active area of our sample were known .{ C=ε_r ε0 A/d }this equation was used to calculate the ε_r.

but the calculated value was lower than one! about 0.000035

I think that our LCR meter must be defective.

what do you think?
 
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  • #2
Its almost definitely higher than 1. How valid is the assumption that the M-S-M structure behaves like a parallel plate capacitor? How does the I-V characteristic of the device look? What do you know about the interface between the metal and the semiconductor i.e. are the built in potentials?
 

1. What is relative permittivity of a semiconductor material?

Relative permittivity, also known as dielectric constant, is a measure of how much a material can store an electric charge when an electric field is applied to it. In semiconductor materials, the relative permittivity is a crucial property that determines the speed of electronic signals and the efficiency of electronic devices.

2. How is relative permittivity of a semiconductor material measured?

The relative permittivity of a semiconductor material is typically measured using a device called a capacitance meter. This instrument applies an electric field to the material and measures the resulting change in capacitance. The relative permittivity is then calculated using this measurement and the known properties of the material.

3. What factors affect the relative permittivity of a semiconductor material?

The relative permittivity of a semiconductor material is influenced by several factors, including its chemical composition, crystal structure, and temperature. Additionally, the relative permittivity can be modified by applying an external electric field or by introducing impurities into the material through a process called doping.

4. How does the relative permittivity of a semiconductor material affect its performance in electronic devices?

The relative permittivity directly impacts the speed at which electronic signals can travel through a semiconductor material. A higher relative permittivity means that the material can store more charge, which can slow down the movement of electrons. This can affect the overall performance and efficiency of electronic devices, particularly in high-speed applications.

5. Can the relative permittivity of a semiconductor material be changed?

Yes, the relative permittivity of a semiconductor material can be modified through various methods. As mentioned before, doping and applying an external electric field can both alter the relative permittivity. Additionally, the relative permittivity can also be changed by varying the material's temperature or by using different processing techniques during fabrication.

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