The electrical conductivity of my sample increases with tempeature, So when I calculate the carrier concentration n it turns out to be negative value.
Does mean that I have n-type compound?
I have obtained High conductivity Ke with T and the same for electrical conductivity and I think that it related to the carrier concentration.
carrier concentration can be calculated by using the formula n=conductivity/ (charge of the carrier x mobility of carrier). here carrier means either electron or hole and the sign of the charge carrier can be obtained by calculating Hall coefficient. if RH is positive the carrier is hole or if the charge is negative the carrier is electron.
This can be done experimentally let us construct a circuit such that a sample for which Hall coefficient can be calculated is connected series with the battery, plug key, ammeter, and voltmeter connected across the sample, then magnetic field applied in perpendicular direction to current. The electric field created perpendicular to both current and magnetic field which can be measured with the voltmeter, if the field is negative then Hall coefficient is negative the charge sign is negative and the field is positive the the charge sign is positive the carrier is hole.
RH = VH * b/(Ix * B)
where b is width of the sample and B is magnetic field
In ceratain cases, Sample has positive lower values of carrier concentration but the RH, has predective positive values at room tempeature and becomes nagative at intermediate and high temperature. In this case we can that I have in the majority n-type compound because RH is almost nagative despite the positive value of carrier concentration in the whole of temperature?
- Badges
- Science topic
- Similar topics
- Higher Education
- Universities