Module 6 : PHYSICS OF SEMICONDUCTOR DEVICES
Lecture 33 : Hall Effect
 
By measuring the current density $ J$, the magnetic field strength $ B$ and the electric field $ {\cal E}$, we may
  determine the carrier density. Since $ J= I/wd$ and $ {\cal E}= V_H/w$, we get
$\displaystyle n = \frac{IB}{qdV_H}$
The direction of Hall voltage depends on the sign of the charge of the carrier. Hall effect, therefore, provides a
  direct way of establishing the existence of holes. We define Hall constant $ R_H$ through
 
$\displaystyle R_H = \frac{1}{nq}= \frac{V_Hd}{IB}$
  If $ \rho$ is the resistivity of the material of the strip, the mobility of the carrier is given by
 
$\displaystyle \mu = \frac{1}{\mid\rho nq\mid}= \frac{\mid R_H\mid}{\rho}$
 
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