Study On The Effect Of Gd Doping On Photoelectric Properties Of Conductive Zinc Oxide Powders

Antistatic thermal control powder has the advantages of high reflectivity,high infrared radiation,high conductivity,economic and environmental protection,and has been widely used in aerospace,petrochemical,electronic power and other fields.Aluminum-doped zinc oxide(ZnO:Al)powders have the advantages of low cost,easy preparation and adjustable photoelectric properties,and are one of the ideal materials for the preparation of antistatic thermal control powders.However,in the preparation process of ZnO:Al conductive powder,it is easy to produce deep level defects such as oxygen vacancy,which leads to the decrease of its reflectivity.Therefore,how to reduce the defect density of ZnO:Al conductive powder and improve the reflectivity is the main problem in this research field.In this paper,Al and Gd codoped ZnO conducting powders(ZnO:Al&Gd)were prepared by coprecipitation method.The effects of doping concentration,sintering temperature and other factors on the optical and electrical properties of ZnO conducting powders were systematically studied.Specific research contents are as follows:1、Regulation and mechanism of Gd and Ce doping on photoelectric properties of ZnO powders..Firstly,the influence of Gd doping concentration was studied.When the Gd doping concentration is within the range of 0.1-1%,the reflectivity of ZnO powder significantly increases.When the Gd doping concentration is 0.2%,the reflectivity reaches 92%.Compared to undoped samples,the whiteness increases by nearly 7%.X-ray photoelectron spectroscopy(XPS)testing showed that the concentration of oxygen vacancy defects in Gd doped ZnO powders decreased.Secondly,the influence of sintering temperature was studied.In the range of 700-900℃,the increase in sintering temperature promotes the doping efficiency of Gd,further reducing the concentration of oxygen vacancy defects.On the other hand,it can provide free electrons,thereby improving the reflectivity and conductivity of ZnO powder.Further increase in annealing temperature will lead to acceptor defects such as zinc vacancies in ZnO powders,reducing the photoelectric properties of the powders.Finally,the photoelectric properties of Ce and Gd doping on ZnO powder were compared.It is found that Gd doping has better enhancement effect on the reflectance of ZnO powder than Ce doping under the same doping concentration and sintering temperature2.Effect of Gd doping on photoelectric properties of ZnO:Al conductive powders.Firstly,the effect of Gd doping concentration on the optical and electrical properties of ZnO:Al conductive powders is studied.It is found that appropriate Gd doping can also improve the whiteness of ZnO:Al powder.When the electrical resistivity is all 1Ω·m,the whiteness of ZnO:Al powder and Gd doped ZnO:Al powder are 82% and 90%,respectively.XPS and photoluminescence spectra show that the main reason for the improvement of powder whiteness is that Gd doping can reduce the oxygen vacancy defect concentration from 65% to 55%,and the defect absorption and luminescence peak intensity of ZnO:Al powder are significantly reduced.Secondly,the effect of sintering temperature on Gd-doped ZnO:Al conductive powder is studied.It is found that the doping efficiency of Al and Gd is improved when the sintering temperature increases from 700 ℃ to 900 ℃,which further enhances the reflectivity and conductivity of ZnO powder.