NiO/ZnO Heteroiunction UV Detector Via Combustion Synthesis Of NiO

During the past decades,ultraviolet detection technology as another important photoelectric detection technique after the infrared detection technology and laser detection technology has received extensive attention.Compared with silicon-based ultraviolet detector,UV detector made by wide bandgap semiconductor material becomes the focus of research.ZnO is a typical wide bandgap semiconductor and ZnO ultraviolet detector which has a lot of merits like:a low cost,simple preparation and excellent performance etc,has got more and more extensive research.But due to the technical barriers of preparation of p-type ZnO materials,homogeneous structure of ZnO ultraviolet detector is difficult toachieved.So,people focused on heterojunction structure of ZnO ultraviolet detector.Compared with other wide bandgap semiconductor materials such as SiC,GaN,NiO materials which has a physical characteristics of extensive sources,friendly to environment,stable properties and also has a electrical performance of wide band gap,high electron mobility,preventing electrical flow and transfering holes,has got people's attention gradually.So,in view of the ZnO/NiO heterojunction ultraviolet detector research is of practical significance.Solution combustion method is used to prepare NiO materials.Pulsed laser deposition is used to prepare ZnO thin film,and we used hydrothermal method prepare ZnO nanowires.Finally,we combined the ZnO and NiO and fabricated the ZnO/NiO heterojunction ultraviolet detector.In this thesis,we fabricated two kinds ultraviolet detectors of different morphology of ZnO/NiO heterojunction structure.1.The solution spin coating method and pulsed laser deposition method were used to the preparation of ZnO seeds layer,and the hydrothermal method was used to grow the ZnO nanowires,we found the ZnO nanowires prepared by pulsed laser deposition method and hydrothermal methodtor were more uniform and vertical.The rate effort of NiO precursor liquid attached to the nanowires was also studied.When the rate was about 10 ?m/s,NiO could fully adhere to the line,and nanowires remained vertical topography.Finally,we adapt the way of solution combustion method and prepared ZnO/NiO heterojunction structure to fabricate ZnO/NiO heterojunction ultraviolet detector of nanowires type.UV photodetector with such a simple structure showed repeatable and favorable detection sensitivity of 13.3 at 0.9 V to the 365 nm UV light.2.By PLD.combustion method,we prepared ZnO:Al films and NiO films,and fabricated the NiO/ZnO heterojunction ultraviolet detector of thin film type.This film ultraviolet detector's sensitivity was 4.We found that detector sensitivity of ZnO nanowires UV detector is more sensitive than ZnO films UV detector.Then the cause was studied.The possible reason is that the nanowires' crystal quality is higher than the thin film made by PLD,so,the defect cause light carrier trapping and composite.