Structural, Optical, and Electrical Properties of Kësterite/Zinc Oxide Heterostructures

Abstract

ABSTRACT In this work, kësterite thin films were deposited on soda lime glass substrates by spin coating from a sol-gel precursor without further sulfurization. Zinc oxide films were prepared by an electrochemical technique, and these films were then used to fabricate kësterite/zinc oxide heterojunc-tions. X-ray diffraction analysis showed that the as-deposited kësterite films were poorly crystallized with the presence of binary metal sulfides. Annealing in vacuum greatly enhanced the crystalline of the films and eliminated the binary phases. The properties of kësterite/zinc oxide junctions were analyzed by current voltage as well as capacitance and conductance versus applied voltage and frequency measurements. The current voltage characteristics exhibited a rectifying behavior. On the other hand, the capacitance of the junction changed with frequency, suggesting the presence of deep states within the junction.