Electrical characterization of transparent p–i–n heterojunction diodes

Abstract

Transparent p–i–n heterojunction diodes are fabricated using heavily doped, p-type CuYO2 and semi-insulating i-ZnO thin films deposited onto a glass substrate coated with n-type indium tin oxide. Rectification is observed, with a ratio of forward-to-reverse current as high as 60 in the range −4–4 V. The forward-bias current–voltage characteristics are dominated by the flow of space-charge-limited current, which is ascribed to single-carrier injection into the i-ZnO layer. Capacitance measurements show strong frequency dispersion, which is attributed to i-ZnO traps. The diode structure has a total thickness of 0.75 μm and an optical transmission of ∼35%–65% in the visible region.