Ambipolar Devices

Abstract

In many devices the concentration of holes and electrons are more or less of the same order of magnitude. In this case both types of carriers have to be considered in the Monte Carlo model. The scattering rates and the band structure of the two species of charged particles differ considerably, as we have seen in Chapters 3 and 4. We now have to define superholes in a similar way as superelectrons; each superhole represents a number of real ones. Two kinds of mobile particles enter the charge distribution term of the field equation; for each field-adjusting time step, transport histories of all the electrons and the holes have to be simulated. During simulation it is, for each time step, recommended to follow all the electrons first, then the holes. The reason for this will become clear when studying recombination of electron-hole pairs.