Electro-optical Properties of All-oxide P-CuAlO2/n-ZnO: Al Transparent Heterojunction Thin Film Diode Fabricated on Glass Substrate

We report on the fabrication of all transparent heterojunction thin film diodes of the form glass/n-ZnO: Al/p-CuAlO2 produced by a combinatorial chemical and physical technique and on a study of their electro-optical properties. The n-ZnO: Al layer was deposited by a sol-gel-dip-coating process whereas the p-CuAlO2 layer was deposited by direct current sputtering techniques. The diode structure, with a total thickness of 1100 nm showed around 60% transmittance in the visible region. The current-voltage characteristics of the device showed a rectifying nature, with a low turn-on voltage around 0.8 V, having a rectification ratio \u3e 50 at ± 2 V. The low turn-on voltage and moderate visible transmittance of the transparent diode indicate its potential application in the field of “Transparent” or “Invisible Electronics”