Electrical properties of the NiFe2O4/n-CdTe heterojunction

NiFe 2 O 4 / n -CdTe heterojunctions were fabricated by spray pyrolysis of nickel and iron salt solutions on n -CdTe substrates, which were structurally improved by magnetron sputtering of thin ITO films and creating ITO/NiFe 2 O 4 / n -CdTe heterostructures with a current rectification ratio RR ≈ 1.03·10 6 at voltages | V | = 1 V. The I-V -characteristics of the fabricated structure were analyzed. The height of the potential barrier qV b = 1.05 eV, which determines the diode properties of the structure, was determined. It was established that when forward biased to voltages V = 0.35 V, an over-barrier current flows in the heterostructure, which at V ≈ 0.7 – 1 V changes to electron tunneling through a narrowed barrier. The role of cadmium vacancies in the process of electron tunneling from the conduction band of NiFe 2 O 4 during the formation of reverse current has been elucidated. The C-V -characteristics of ITO/NiFe 2 O 4 / n -CdTe heterostructures with an inversion layer on the n -CdTe side were analyzed. A model of the energy diagram of a heterostructure is presented, which explains the electrical properties well. • NiFe 2 O 4 / n -CdTe heterojunctions were made by spray pyrolysis of nickel and iron salts. • Heterojunctions with a current rectification ratio of ∼ 10 6 were produced. • The main mechanisms of current flow in NiFe 2 O 4 / n -CdTe were established. • The C-V -characteristics confirm the existence of an inversion layer.