Preparation And Photoelectiric Properties Of Ag Nanowire/ZnO Thin Film Ultraviolet Detector

Ultraviolet detectors have important applications in the fields of national defense,aerospace,etc.ZnO has a large gap in the direct gap,and the intrinsic response band is located in the ultraviolet region.ZnO has high exciton binding energy and the cost is low,which is excellent for preparing ultraviolet deterctor.Because ZnO is an intrinsic n-type semiconductor material,its homogeneous p-type semiconductor is difficult to realize.High-quality homogenous p-n junction device cannot be realized.The performance of the detector is poor and the response is low.In this paper,the ALD method is used to prepare high performance thin film.The ZnO thin film is enhanced by the surface plasmon effect of the Ag nanostructure to the conventional photoconductor structure ZnO ultraviolet detector.The high performance ZnO thin films were prepared by ALD method and the Ag nanowire/ZnO layer structure was prepared.The bonding morphology of ZnO on Ag nanowires was studied,and the changes of Ag nanowire/ZnO layer structure before and after heat treatment were studied.An Ag nanowire/ZnO thin film detector was prepared and its photoelectric properties were investigated.ZnO thin films were prepared by ALD deposition,and ZnO thin films with optically dominant non-polar structures were prepared.The deposition thickness per crystal of ALD deposition was 0.194 nm/cycle.As the ALD deposition progresses,the dominant crystal plane gradully becomes the?100?crystal plane.Oxygen vacancies and internal defects of the ZnO thin film are improved by heat treatment.A ZnO thin film ultraviolet detector is prepared.When the ZnO thin film is deposited to a thickness of 300 deposition cycles or about 58 nm,the ZnO thin film ultraviolet detector has the best photoelectric performance.The responsivity?5V,365 nm?is 13.3 A/W,and the light detection value is 9.6×10⁹ Jones.The ratio of light to dark current is 47.When the working voltage is 5V,the response light is365nm,the maximum optical responsivity is 15.7A/W,the UV-visible suppression ratio is 189 times.The response speed is slower,and the response time is greater than 400s,which has a relaxation phenomenon.The Ag nanowire/ZnO enhanced UV detector is prepared.When the Ag nanowire/ZnO layer has a heat treatment temperature of 600°C,the detector has the best comprehensive performance.The light responsivity?5V,365nm?can reach120.4A/W.The ratio of light to dark current is 6686,the light detection value is3.4×10¹¹ Jones.As the heat treatment temperature increases,the response speed of the detector increases.When the operating voltage is 5V and the response light is350nm,the maximum optical responsivity is 131A/W.The UV/visible suppression ratio is up to 1824 times.When the ZnO thin film is deposited to a thickness of 400deposition cycles or about 72 nm,the ZnO thin film ultraviolet detector has the best photoelectric performance,the responsiveness?5V,365 nm?is 365 A/W.Comparing the photoelectric properties and the optimal response wavelength of ZnO thin film detectors and enhanced ZnO thin film detectors,it is found that the optical response of enhanced ZnO thin film detectors is increased by about 100 times.The strongest response band in the ultraviolet region has undergone a blue shift,and the UV-visible suppression ratio and photo-response rate have also been greatly improved.It is shown that the surface plasmon effect of the nano-Ag structure does enhance the photoelectric performance of the ZnO thin film detector.