vacancies on the cation sublatticeex) 금속이온의 제거(removed metal ion)- + - + - ++ - + - + - Vm' : means that a c ... ( " ). : positive charge ( " )e' : electron in conduction bandh. : hole in valance bandVmx : vacancy left by ... }}^{2} Ci} over { KT }(-{d PHI } over {dx})전도도(Conductivity)는 아래의 식으로 표현I= sigma ```(-{d PHI } over {dx