Research On The Characteristics Of High Performance Solar Blind Deep Ultraviolet Photodetector Based On Zn₂GeO₄ Nanowire Networks

The ternary oxide Zn₂GeO₄ has a bandgap width of 4.68 eV,capable of shielding the UV-A and UV-B bands?290-400 nm?in the UV band and only responding to the UV-C band?200-290 nm?.Zn₂GeO₄ nanowires have a large specific surface area,fast charge transport properties and efficient light absorption,meanwhile,the interconnections in the nanowire arrays lead to junctional barriers that dominate charge transport between the nanowires.Irradiation of the ultraviolet light can cause the nanowires The fast tuning of the junction barrier height has great potential in the field of deep ultraviolet photodetection.In this paper,the preparation of Zn₂GeO₄ nanowire network and the use of non-transfer preparation of solar-blind DUV detector photoelectric properties were studied.The main contents and acquired innovative achievements are as follows:The effect of different growth pressure on the preparation of Zn₂GeO₄ nanowire network was studied.The nanosized gold layer with 3nm thickness was used as catalyst to prepare Zn₂GeO₄ nanowire network under four pressure gradients of 0.5 kPa,1 kPa,2 kPa and 5 kPa.Through the characterization and analysis of the samples,we found that Zn₂GeO₄ nanowires are VLS growth mechanism,and the pure Zn₂GeO₄ nanowires can only be obtained under low pressure environment.With the increase of the growth pressure,the ZnO component gradually appears in the sample.The preparation process of the lateral Zn₂GeO₄ nanowire without catalyst based on columnar electrode was studied.A substrate structure with columnar array electrodes was designed.The substrate structure is the basis for the lateral growth of Zn₂GeO₄ nanowires into a network.Finally,a columnar electrode-based lateral Zn₂GeO₄ nanowire array was successfully prepared in the absence of catalyst to achieve the growth of nanoscale semiconductor circuits.Finally,through theoretical analysis,it is found that the higher binding energy at the edge of the electrode and the larger vapor concentration of the raw material at the edge of the columnar electrode are the key factors for the growth of Zn₂GeO₄nanowires laterally at the edge of the columnar electrode to form the nanometer net.The growth of Zn₂GeO₄ nanowires based on quartz was studied.In the experiment,Zn₂GeO₄ nanowires were successfully grown on quartz substrates,laying a foundation for the wider application of Zn₂GeO₄ nanowires in the field of nanodevices.The absorption and response bands of Zn₂GeO₄ nanowires were measured.The absorption and absorption spectra of Zn₂GeO₄ nanowires were obtained.The UV-C responses of Zn₂GeO₄ nanowires to 200nm-275 nm band were obtained.The dependence of growth pressure on the performance of solar blind deep ultraviolet photodetectors was studied.A solar blind DUV detector based on Zn₂GeO₄ nanowires grown under different pressure gradient was prepared and the photoelectric properties of the detector were tested.It was found that with the reduction of growth pressure,the performance of the prepared photodetector was improved.The results show that the proposed method has the best performance of 5.11×10³A·W-1 with excellent solar blindness response,2.45×10⁶ external quantum efficiency,2.91×10¹¹ Jones detection rate,11 times optical gain and fast response time(?_rise?300 ms,?_decay?86 ms)high-performance solar blind deep ultraviolet photodetectors.