Field emission properties of Al-doped ZnO nanosheet based on field emitter device with UV exposure

In this study, aluminum (Al)-doped zinc oxide (ZnO) nanosheets were synthesized on a ZnO/glass substrate under different growth temperatures using a modified aqueous solution method. The field emission and physical properties of Al-doped ZnO nanosheets were then investigated. Results indicated that high growth temperature improves the quality of Al-doped ZnO nanosheets. Moreover, the photoluminescence intensity of the sample's ultraviolet (UV) emission peak (growth temperature at 60 °C) was stronger compared with those of other samples. However, its broad, deep-level green emission band was weaker. The turn-on field and field enhancement factor (β) of Al-doped ZnO nanosheets were 3.8 V μm−1 and 4760, respectively. The UV illumination of the Al-doped ZnO nanosheets decreased the turn-on electrical field from 3.8 to 3.3 V μm−1 and elevated the β from 4760 to 7501.