Control of vanadium-doping concentration in ZnO film for performance enhancement of VZO/CuO heterojunction diode

초록

In this study, vanadium (V) doping into ZnO was utilized to tackle the limited performance of ZnO/CuO heterojunction diodes. V-doped ZnO (VZO) films with variable V concentrations were elaborately prepared by co-sputtering, and their properties were systematically investigated. Intriguing phenomena such as grain refinement, band gap widening, and carrier concentration increase were observed as V concentration increased. Various VZO/CuO heterojunction diodes were fabricated by a combination of co-sputtering and reactive sputtering. An optimal heterojunction with a V content of 0.28 at% exhibited a very high rectification ratio of 686, low ideality factor of 2.63, and a very low reverse saturation current of 3.79 & times; 10(-13) A. Its rectification ratio was approximately 73-fold higher than that of ZnO/CuO diode. These results demonstrate that V doping can effectively tune the charge transport properties of ZnO for optimizing the current rectification performance of oxide-based heterojunction diodes.

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