Nanografi Nanotechnology

Doping means the introduction of impurities into a semiconductor crystal to modify the conductivity. The two important elements that silicon can be doped with are boron and phosphorus. The dopant is integrated into the lattice structure of silicon and the number of outer electrons define the type of doping. Elements with 3 valence electrons are used for p-type doping, in this case is boron; 5-valued elements for n-doping, in this case is phosphorus. By doping boron or phosphorus the conductivity of silicon can be increased. Phosphorus has an outer electron more than silicon. Four outer electrons combine with ever one  silicon  atom, while the fifth electron is free to move and serves as charge carrier.                                                               In contrast to the free electron due to doping w...