hi, holes are the absence of electrons in the lattice, right? then how come we say holes have a +ve charge? shouldnt it be zero? also, why is the mobility of electrons more than holes? thanks
This is what I wrote for another thread: As for the other question, I'm guessing it's something to do with the magnitude of their effective masses.
i should ve searched for that before posting a new thread. it makes sense, yes.. what would the effective mass of a hole be??
Where would you usually find a hole? And where would you usually find an electron? Where == which band? Yes, the effective masses of holes and electrons are different. The mobility is a function of the effective mass, which is a theoretical tool brought in to simplify the description of a charged particle in a crystal. Classically, the concept of an effective mass is analogous to that of a 'psuedo force' in Newtonian mechanics. In the simplified, Drude model, the mobility is inversely proportional to the effective mass, for a fixed mean free time.