Assumptions regarding the majority carrier concentration

In deriving eqs. 2.8 and 2.9, it was assumed that the majority-carrier concentration was equal to the density of the dopants throughout the QNRs. For this to be so, low – injection conditions have to be fulfilled: that is, the perturbation of the majority carrier concentration due to light generation or carrier injection must be small, so that

Подпись: (2.102) (2.103) n ~ N0, (in и-type material) p = Na – (in p-type material)

In other words, the density of free charge carriers is equal to the density of ionised dopants. This approximation is not valid for illumination by concentrated sunlight or high forward-bias voltages. If, in addition, the energy level of the dopant lies near the relevant band edge, all the dopants will be ionised at room temperature, and in this case



Updated: July 29, 2015 — 7:39 pm