Study Of Photoelectric Properties Of One-dimensional ZnO And TiO₂ Nanorod Arrays

The metal oxides ZnO and TiO₂ with wide band gap have been widely used in biosensors,photocatalysis,solar cells,resistive memory,and ultraviolet light detectors due to their high physical and chemical stability,good radiation resistance,and low price.One-dimensional nanostructured ZnO and TiO₂ have characteristics of large specific surface area and carrier-oriented transport.It is difficult to be accurately controled that the morphology of one-dimensional nanostructures grown by chemically grown and the uniformity of the thin film,the contact resistance in the optoelectronic device is larged,limiting the carrier transport and the device's operating stability.A large number of surface states and defect states as charge recombination centers hinders the photogenerated electron-hole pairs transport and separation,affecting the conversion efficiency of photodetecting devices and solar cells.Based on the control the quality process of one-dimensional nano-film growth,the Ag/ZnO nanorod arrays(NRs)Schottky junction and Au/TiO₂ NRs Schottky junction were constructed,and the ultraviolet light response performance was studied under electric field drive.The effect of defects on the conductive behavior of ZnO NRs films and TiO₂ NRs films under the synergy of light and electric fields were studied.The main research contents and results of this dissertation are as follows:(1)The effect of AZO seed layer with different thicknesses on the morphology,crystalline quality of ZnO NRs,and the ultraviolet response characteristics of the Schottky junction of Ag/ZnO NRs was studied.The ZnO NRs grown on the three-layer AZO seed layer have shown better density,higher crystal quality,higher carrier concentration,narrow depletion region,and lower interface charge transfer resistance,ZnO NRs have a significant upward shift in the position of the conduction and valence bands.The responsivity and photocurrent of the Schottky junctions based on ZnO NRs grown on the three-layer AZO seed layer are the largest.(2)The effect of the amount of absolute ethanol stabilizer added on the morphology,crystalline quality of TiO₂ NRs and the ultraviolet response characteristics of the Schottky junction of Au/TiO₂ NRs was studied.TiO₂ NRs with 10 m L of absolute ethanol have the best crystalline quality the highest carrier concentration,the lowest interface charge transfer resistance and the highest Fermi level.The rectification characteristics and light response performance of the Schottky junctions based on TiO₂ NRs with 10 m L of absolute ethanol are better,and the Schottky junctions exhibit the responsivity reaches 8.9 A/W under weak ultraviolet light at 376 nm at-1 V bias.(3)The conduction behavior of ZnO NRs and TiO₂ NRs under the synergy of light and electric fields was studied.It was found that the device based on the ZnO NRs film exhibited a sudden rise in current under a cyclic electric field of 0 V?+ Vmax?0 V?-Vmax?0 V,which could satisfy the requirements of resistive memory applications.The resistance window of both structures increases,and the operating voltage decreases.The devices based on TiO₂ NRs film show the opposite synapse-like behavior in dark state and light,indicating that the incident light can regulate the electronic synaptic behavior provides a new strategy for the realization of synaptic functional devices.