Variable range hopping (VRH) conductivity, ac conductivity and dielectric studies on Sm3+ doped Cd0.8Zn0.2S semiconductor compounds

Abstract

Polycrystalline semiconductor compounds of Cd0.8Zn0.2S and Sm3+ (0.01, 0.02, 0.03, 0.04 and 0.05mol%) doped Cd0.8Zn0.2S samples have been synthesized by a controlled co-precipitation technique. The samples are characterized by X-ray diffraction (XRD). DC conductivity studies were performed in the temperature region 77–300K by using a two probe method. The dc conductivity plots show the Arrhenius behavior with three different activation energies (Ea) in three different temperature regions (I (300–220K), II (220–160K), III (160–105K), and they exhibited the variable range hopping conduction (VRH) mechanism at low temperature region (105–77K). From the impedance, and dielectric measurements bulk resistance (Rg), capacitance (Cg), relaxation time (τ) and dielectric constant (ε̕) parameter values were calculated. And explained their variations with temperature and dopant (Sm3+) concentration changes.