How to distinguish n/p type semiconductor

[eclab.rxd]

Homework Statement

Hello, everyone! As a rookie here, I want to ask a question for help.
As for doped semiconductor, it is easy to find the answer based on the atom property. But for a intrinsic semicondutor, it seems hard to do so. I'd like to know what can be done to distinguish a n-type semiconductor to a p-type one.

Homework Equations

Did it happen to you that a material reported n-type was claimed p-type in another article?

The Attempt at a Solution

 

[jbsteele]

In order to distinguish between a n-type and a p-type semiconductor, one can use various techniques such as Hall measurements, thermoelectric measurements, or electrical transport measurements. The Hall effect is one of the most commonly used techniques for distinguishing between the two types of semiconductors, as it measures the transverse voltage that is generated by an applied magnetic field. Thermoelectric measurements involve measuring the Seebeck coefficient of the material, which is the ratio of the potential difference between two points in the material to the temperature difference between them. Electrical transport measurements involve measuring the conductivity of the material and its response to an applied electric field. By looking at the results of these measurements, one can determine whether a material is n-type or p-type.

 

[kerimek]

Hello! I can provide some guidance on how to distinguish between n-type and p-type semiconductors.

First, it is important to understand the concept of doping in semiconductors. Doping is the process of intentionally adding impurities to a semiconductor material in order to change its electrical properties.

In n-type semiconductors, the material is doped with impurities that have extra electrons, such as phosphorus or arsenic. These extra electrons are called donor electrons and they increase the number of free electrons in the material, making it conductive. On the other hand, in p-type semiconductors, the material is doped with impurities that have fewer electrons, such as boron or gallium. These missing electrons are called acceptor electrons and they create "holes" in the material, making it conductive.

One way to distinguish between n-type and p-type semiconductors is by using a Hall effect measurement. This method involves applying a magnetic field to the semiconductor and measuring the voltage created by the movement of charge carriers (electrons or holes) in the material. In n-type semiconductors, the current is carried by electrons, so the voltage is negative, while in p-type semiconductors, the current is carried by holes, so the voltage is positive.

Another way to distinguish between the two types is by using a diode test. A diode is a device made of a p-n junction, which is formed by joining a p-type and an n-type semiconductor. By applying a small voltage to the diode, the direction of the current flow can be determined. In an n-type semiconductor, the current flows from the negative end to the positive end, while in a p-type semiconductor, the current flows from the positive end to the negative end.

Lastly, it is important to carefully examine the material's properties and its fabrication process to determine its type. For example, n-type semiconductors tend to have a higher electron mobility (ability to conduct electricity) compared to p-type semiconductors, and their fabrication process involves adding impurities such as phosphorus or arsenic. On the other hand, p-type semiconductors have lower electron mobility and their fabrication process involves adding impurities such as boron or gallium.

In summary, to distinguish between n-type and p-type semiconductors, one can use methods such as Hall effect measurement