Structure formation and mechanisms of DC conduction in thermally evaporated nanocrystallite structure ZnIn2Se4 thin films

Abstract

Abstract ZnIn 2 Se 4 is of polycrystalline structure in as synthesized condition. It transforms to nanocrystallite structure of ZnIn 2 Se 4 film upon thermal evaporation. Annealing temperatures influenced crystallite size, dislocation density and internal strain. The hot probe test showed that ZnIn 2 Se 4 thin films are n-type semiconductor. The dark electrical resistivity versus reciprocal temperature for planar structure of Au/ZnIn 2 Se 4 /Au showed existence of two operating conduction mechanisms depending on temperature. At temperatures >365 K, intrinsic conduction operates with activation energy of 0.837 eV. At temperatures 2 Se 4 /p-Si/Al diode at different temperatures ranging from 293–353 K have been investigated. Results showed rectification behavior. At forward bias potential 2 Se 4 film over a potential barrier of 0.28 V takes place. At forward bias potential >0.2 V, single trap space charge limited current is operating. The trap concentration and trap energy level have been determined as 3.12×10 19 cm −3 and 0.24 eV, respectively.