For Semi-Conductor in Figure 1b, a thermoplastic dielectric is used in modern semiconductor process for doping to get an N-type semiconductor. N-type is a semiconductor with electrons (negative charge) and the P-type carriers is a semiconductor with holes (positive charges). The voltage difference, ( ), produced across the terminals of an open circuit made from a pair of dissimilar materials, whose two junctions are held at different temperatures, is directly proportional to the difference between the hot and cold junction temperatures. The voltage or current produced across the junctions of two different materials is caused by the diffusion of electrons from a high electron density region to a low electron density region, as the density of electrons is different in different materials. The conventional current flows in the opposite direction. The relationship can be described as follows.