| There are six isomers in Ga2O3.Among them,the monoclinic phaseβ-Ga2O3 has been widely studied because it has the best thermodynamic stability and has been used as a single crystal substrate.β-Ga2O3 not only has an ultra-wide band gap of 4.9 eV,but also has excellent characteristics such as high temperature resistance and high pressure resistance,and insoluble in acid and alkali.So far,theβ-Ga2O3 materials have been reported to have various morphologies:bulk single crystals,one-dimensional nanowires and nanoribbons,two-dimensional thin films,and nanowire arrays.However,high quality bulk single crystals and films are difficult to prepare,while nanostructured materials are not easy to handle.Therefore,it is very helpful to prepare high-quality,easy-to-operateβ-Ga2O3.In this paper,a high qualityβ-Ga2O3 single crystal microwire is prepared by chemical vapor deposition.The average diameter of the material is about 10μm and the longest is up to 1cm.The micewire in this scale can be easily seen by the naked eye and can be conveniently operated with tweezers.Subsequently,the UV detection performance of gallium oxide microwires was studied by fabricating detectors with different structures.In this paper,Schottky structures and p-n junction structures based on gallium oxide microwires were fabricated to study the detection capability of gallium oxide microwires.The results are as follows:First,we have grown ultra-long gallium oxide micro-wires on quartz glass substrates by chemical vapor deposition.Most of the gallium oxide micro-wires have a diameter of 10-30μm and a length of 5-8 mm,even up to 1 cm.The X-ray diffraction spectrum was used to determine that the Ga2O3 micron line grown by the method was a monoclinic（β）gallium oxide single crystal.It can be seen from the SEM image that the surface of the gallium oxide microwire is smooth and flat to a well-crystallized gallium oxide microwire,and the EDX elemental analysis determines that the material contains the O element and the Ga element.The GaN-mirror microfilaments grown by HR-TEM image and selected area electron diffraction were determined to be single crystals with good crystal quality.Finally,the ultraviolet-visible absorption spectrum was used to determine that the gallium oxide micron lines have absorption of light in the solar blind region of about 250 nm.Secondly,we made In-Ga2O3-In structured photoconductive detector and PEDOTs:PSS/Ga2O3 self-driven solar blind UV detector.And the performances of these device were characterization in detail.Through testing,we learned that the ultra-long Ga2O3micron line has very small dark current,at pA level,and has a very good light response.The light-dark ratio can reach three orders of magnitude,but the corresponding time is very slow,and it needs to be added.The bias is maintained.The Au/Ga2O3 structure of the solar blind UV detector can achieve self-driven detection and has a high light-dark ratio and responsiveness at 0 V,but due to the morphology of the gallium oxide micro-wires,gallium oxide and physical deposition It is difficult to form a good contact between the films,and the repetition rate of the device is not high.Finally,we found through research that the material can be combined with the Ga2O3 micron wire to form a p-n junction-conductive polymer PEDOTs:PSS.Freshly prepared PEDOTs:PSS is in the liquid phase,which solves the contact problem between the micro-wire and p-type materials,and PEDOTs:PSS can form a p-n junction with the micro-wire by drying.Tested PEDOTs:PSS has no photoresponse under any light exposure,avoiding the device’s ability to introduce other wavelengths.The tested device has very good self-driven day-light UV detection performance,and the light-dark ratio can reach 4 orders of magnitude at 0 V.The detector not only has a larger improvement than In-Ga2O3-In（can perform 0 V self-drive detection,the response speed is greatly improved）,and has high responsiveness and heterogeneity ratio,and exceeds the current Devices in internationally published journals.The device has a high responsiveness of 0 V（2.6 A/W）and a high detection of 2.2×1013 at a small bias.At the same time,the device has an ultra-high heterogeneity ratio:the UV-visible heterogeneity ratio is about 105,and the blind-visible blind heterogeneity ratio is 104.At the same time,the device also has a high response speed:rise time 315μs,fall time 4ms.In summary,we prepared ultra-long gallium oxide micro-wires with a length of cm and a width of 10μm by chemical vapor deposition.The micron wire is a single crystal,and has the advantages of low manufacturing cost and operation with tweezers under the naked eye,and reduces the application cost of the Ga2O3 single crystal material.At the same time,we have prepared different types of solar blind UV detectors,which use p-type conductive polymer PEDOTs:PSS and micro-wires to synthesize pn junction detectors with high responsivity of 2.6 A/W and UV-visible rejection of 105.Compared with the fast response speed（rise time 315μs,fall time 4 ms）. |
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