Електро- та фотопровідність монокристалів сполук Me2TeBr6(I6), де Me – K, Rb, Cs, TI(I)

Abstract

Electro- and photo-conductivity of the monocrystals of the compounds Me2TeBr6(I6), where Me – K, Rb, Cs, Tl(I), have been investigated. It was established that in the studied temperature range the intrinsic conductance has not been achieved. From the slope of the plots lgs=f(103/T), the values of activation energy of the compounds have been estimated. It was found that only three of the eight title compounds (Tl2TeBr6, Tl2TeI6 and Cs2TeI6) are sensitive to lighting, and spectral distribution of photo-conductivity has been determined for them. Band gaps of Tl2TeBr6, Tl2TeI6 and Cs2TeI6 have been determined from the maxima of their photo-conductivity plots, and the obtained Eg values (2.0, 1.45 and 1.46 eV, respectively) are close to those determined from the edges of optical absorption.