Doped ZnO Nanowire Arrays For LED Application:Synthesis And Luminescent Properties

LED has the characteristics of small size,low power consumption,long service life,strong controllability and so on.Zinc oxide(ZnO),one of the typical materials of wide-direct bandgap semiconductor,is favored in the fields of photocatalysis,photodetector,light-emitting diode,laser and other optoelectronic devices because of its high exciton binding energy,green environment,easy preparation and low price.In this paper,chemical vapor deposition(CVD)method was used to prepare ZnO nanowire arrays,assembled two kinds of LED device,explored the appropriate preparation process,and studyed the influence of Sb doping ratio on LED device luminescent performance.The main research contents of this paper are as follows:1.A layer of Sb-doped p-ZnO nanowire arrays was first epitaxy grown on the gold-plated p-GaN substrate by CVD,and its influence on the morphology of nanowires was studied by regulating the proportion of Sb-doped.The results showed that with the increase of doping concentration,the longer the nanowire arrays is.Among them,when the mole ratio of ZnO:Sb₂O₃is 10:1,the growth of the nanowire arrays is the most uniform and orderly,and the length is 650 nm.2.After confirming the successful doping of Sb and p-type conductivity,a layer of undoped ZnO nanowires arrays was grown by CVD method twice epitaxy to form homogeneous junction LED device.The effects of four different doping ratio on the luminescent performance of LED devices such as photoluminescence(PL)spectrum and electroluminescence(EL)spectrum were studied.The results showed that the near-edge emission peaks in PL spectrum are red-shifted and the defect peaks are blue-shifted after the second epitaxial growth.With the increase of the doping ratio,not only the defect luminescence peak but also the blue emission peak appeared in the EL spectrum of homogeneous junction LED devices,and the blue emission peak gradually became obvious,and the emission peak of different bands was combined to form the emission of warm white light.3.Also using CVD method,on the n-GaN substrate coated with gold film,the solid solubility of doped element in ZnO was increased by the co-doping of Al and Sb double elements to obtain p-type conductive ZnO,so as to form heterojunction LED.The results showed that both energy dispersive spectroscopy(EDS)and X-ray photoelectron spectroscopy(XPS)data could confirm the successful doping of Al and Sb,and it was found that the co-doped ZnO still has good(001)epitaxial growth characteristics.The volt-ampere characteristic(I-V)curve showed that the device had a good rectification characteristic and realized the electrical characteristic of the pn junction with an opening voltage of 3 V.EL spectrum results showed that the co-doped ZnO heterojunction LED realized the emission of orange-red light with the central wavelength of 650 nm.The research paper as ZnO LED light-emitting device performance as the main line,analyzed the effect of Sb doping ratio to the morphology of ZnO nanowire arrays,the PL and EL spectra of homogenious LED,the luminescent performance of Al and Sb after double elements codoping ZnO heterojunction LED,completed the preparation of two kinds of LED device,and studied the luminescent properties of each device.