Enhanced Field Emission Properties of ZnO:Al/SrTiO₃ Perovskite Composite Films by ZnO:Al Film

Abstract

ZnO:Al(Al‐doped zinc oxide)/SrTiO3 composite thin film field emission (FE) devices are fabricated on heavily doped n‐type silicon substrates using a vacuum electron beam evaporation vapor deposition technique and hydrogen plasma treated technique. The morphology and thickness of SrTiO3 film and ZnO:Al film are controlled by adjusting and optimizing the growth conditions, deposition time, and post‐treatment conditions. FE experimental results show that the addition of ZnO:Al films can significantly improve the FE properties of ZnO:Al/SrTiO3 composite film. The maximum current density of the FE sample increases from 230 μA cm−2 of the monolayer SrTiO3 film sample, which is treated by hydrogen plasma (H–SrTiO3) to 951 μA cm−2 of the ZnO:Al/H–SrTiO3 composite film sample, which increases by more than 4 times. Meanwhile, at the applied electric field intensity of 3.6 V μm−1, the FE current density of ZnO:Al/H–SrTiO3 composite film is 48 times that of monolayer H–SrTiO3 film. Each field emission sample device has good working stability and experimental repeatability.