Consider a semiconductor sample with a rectangular cross section as shown in the figures, a current is flowing in the x -direction and a magnetic field is applied in the z -direction. The resulting Lorentz force will accelerate the electrons (n -type materials) or holes (p -type materials) in the (− y) direction, according to the right hand rule and set up an electric field ξ y. As a result there is a voltage across the sample, which can be measured with a high-impedance voltmeter. This voltage, V H, is called the Hall voltage. V H is negative for n -type material and positive for p -type material.