In-situ Growth of Gallium Oxide Nanoarrays on Glass Fiber Fabrics and Study of Their Flexible Solar Blind UV Detectors

Author:Wang Shun Li

Supervisor:goran ungar


Degree Year:2019





Gallium oxide is a new type of wide-band gap semiconductor material,with a bandgap width of 4.9 eV and a corresponding wavelength of 253 nm.It is a natural solar blind ultraviolet detection material.In recent years,gallium oxide has attracted more and more researchers’attention and become a research hotspot.At present,the solar blind detector based on high crystalinity gallium oxide material has high chemical stability and thermal stability,but usually is based on alumina and quartz and other rigid materials as the substrate,unable to bend,limiting the application range of the device.With the continuous pursuit of portable,recreational and healthy wearable electronic devices,flexible photoelectronic textiles have a huge market prospect in the future,and the growth of gallium oxide with high crystalness directly on the flexible substrate has important scientific significance and practical value.In this paper,focusing on the basic physical properties of gallium oxide material and combining with the characteristics of the textile discipline of our university,the in-situ growth of high-crystallinity phase Ga2O3 nanorod arrays and nanowires on glass fiber fabric and its application in the flexible solar blind ultraviolet detector were studied,and the following results were obtained:(1)High crystallinity Ga2O3 nanorod arrays were grown on a rigid substrate and its solar blind detector was investigated.The GaOOH nanorod arrays were in situ grown on the FTO substrate by hydrothermal method,and after annealing at 400℃and 700℃,theα-Ga2O3 and more stableβ-Ga2O3 nanorod arrays were obtained.Photoelectrochemical solar blind UV detectors based onα-Ga2O3 andβ-Ga2O3nanorod arrays were prepared.The solar blind detector ofβ-Ga2O3 nanorod arrays exhibited better photoelectric performance.(2)High crystallinity phaseβ-Ga2O3 nanorod arrays were in-situ grown on the flexible glass fiber fabric substrate by hydrothermal and annealing methold,and its solar blind photodetector was fabricated.A layer of ITO film was deposited on the glass fiber fabric by magnetron sputtering,and then the GaOOH nanorod arrays were in-situ grown by hydrothermal method,and theβ-Ga2O3 nanorod arrays was obtained by annealing.The results show that theβ-Ga2O3 nanorod arrays grow vertically along the surface of the glass fiber filament cylinder,with uniform and neat morphology and rhomboidal shape,with a cutoff absorption edge of 265 nm and a corresponding band gap of 4.66 eV.A solar blind UV detector based on Ag/ITO/β-Ga2O3NRAs/Ag vertical structure was prepared.Under the ultraviolet light of 254 nm,the photocurrent of the detector increases with the increase of the light power and the bias.When the external bias is 1.0 V and the optical power density is 1.0 mw/cm2,the photocurrent of the detector under bending reaches 13.5 pA,which is almost the same as that in the plane state,indicating that the detector is suitable for use as a flexible photoelectric device.(3)High crystallinity phaseβ-Ga2O3 nanowires were fabricated by chemical vapor deposition on a flexible glass fiber fabric substrate.β-Ga2O3 nanowires and nanograss were prepared by chemical vapor deposition method.The growth process ofβ-Ga2O3 nanowires was controlled by both VLS and VS mechanisms in the low oxygen atmosphere,while the growth ofβ-Ga2O3 nanograss in a high oxygen atmosphere was controlled by VS mechanisms.A solar blind UV detectors based on glass fiber fabric/β-Ga2O3 nanowires was prepared.The detector exhibited high light dark ratio(24.79),high photocurrent density(3.39 A/cm2),high light responsiveness(0.71 A/W),high external quantum efficiency(246.6%)and fast response speed(0.37s,0.19 s)under the ultraviolet light irradiation of 254 nm with the light intensity of1500 W/cm2.