Electrostatic Fields in Reverse-Biased pn - i - pn Structures

Static electric fields are analyzed in GaAs, Si and Ge reverse—biased pn-i-pn structures. Analytic expressions have been derived for the electric field and electric potential in uniformly doped pn-i-pn structures. Both the geometry and the doping profile have been calculated for the structures. Conditions for a drift current-controlled positive feedback between the p-n junction have been established. It is shown that by properly selecting parameters of the reverse-biased pn-i-pn structures it is possible to provide both the desired electric field distribution over the neutral i-region of the structure and the required magnitude of the multiplication factor fro electron-hole pairs of the p-n junctions.