Research Of Preparation And Doping ZnO-TCO Thin Films Performance

ZnO transparent conducting oxide film is a new ?-? direct wide bandgap semiconductor materials,hexagonal wurtzite crystal structure.It has been widely used in communications?microelectronics and optoelectronics and other fields for its excellent photoelectric properties.The research of the preparation method and doping element of ZnO film has always been the research direction in this field.And as the transparent conducting oxide film,it can't both have high conductivity and high transmittance at the same time,especially the transmittance in near-infrared region decrease rapidly.This graduation thesis We try do some work to solve these problem.1?In order to solve the problem of low transmittance in near-infrared region,we use radio-frequency magnetron sputtering to prepar W doping ZnO thin films.First,under the orthogonal experiment method,wo got the corresponding factors:sputtering time 45min?sputtering power 200W?sputtering pressure 1Pa?gas-flow 30 seem?distance of target and substrate 51mm?substrate temperature RT.And under these factors,properties of ZnO:W are:transmittance is 90%in 480-1800nm,resistivity is 5.55×10-4 ?·cm,carrier concentration is 8.8×1019/cm~3.electron mobility is 17.3cm2/Vs.Base on the corresponding factors,we modulate Single or multiple preparation factors,the text of the modulation,refers to in the process of sputtering,before and after the period change single or multiple process conditions,the rest of the process conditions are unchanged.For example sputtering power modulated,the sputtering power of first film is different from the second film,such as first thin film preparation process for the sputtering power 100 W?sputtering pressure 1 Pa?gas-flow 30 seem?distance of target and substrate 51 mm?substrate temperature RT,the second film preparation process for the sputtering power 200 W?sputtering pressure 1 Pa?gas-flow 30 seem?distance of target and substrate 51 mm?substrate temperature RT;expressed in 100W/200W is sputtering power modulated.For example substrate temperature modulated,the substrate temperature of first film is different from the second film,such as first thin film preparation process for the sputtering power 200 W?sputtering pressure 1 Pa?gas-flow 30 seem?distance of target and substrate 51 mm?substrate temperature 100?,the second film preparation process for the sputtering power 200 W?sputtering pressure 1 Pa?gas-flow 30 sccm?distance of target and substrate 51 mm?substrate temperature RT;expressed in 100 ?/RT is substrate temperature modulated.For example two preparation factors modulated,two preparation factors of first film is different from the second film,such as first thin film preparation process for the sputtering power 100 W?sputtering pressure 1.5 Pa.gas-flow 30 sccm?distance of target and substrate 51 mm?substrate temperature RT.the second film preparation process for the sputtering power 200 W?sputtering pressure 1 Pa?gas-flow 30 sccm?distance of target and substrate 51 mm?substrate temperature RT;expressed in(100W?1.5Pa)/(200W?1Pa)is two factors modulated,more factors modulated,the representation and so on.we hope decrease the carrier concentration and increase electron mobility to get the films excellent conductivity and increase the transmittance in near-infrared region at the same time by modulating.(1)Modulating sputtering power are:100W/200W?150W/200W?250W/200W?300W/200W.The innerstress are decreased after modulating.And the thin films preparting by 100W/200W?150W/200W have transmittance 94%?92%?91%,resistivity 6.1×10-4?·cm?7.4×10-4?·cm?9.7×10-4?·cm,carrier concentration 9.7×1018/cm~3?1.3×1019/cm~3?7.1×1019/cm~3,and electron mobility increase to 21.1 cm2/Vs at 100W/200W.So properly dropping the previous sputtering power help decrease the carrier concentration,increase the transmittance in near-infrared region,are the effective modulating factors.(2)Modulating substrate temperature are:100 ?/RT,200 ?/RT.they have transmittance 93%and 91%,resistivity 9.8×10-4?·cm and 1.3×10-3?·cm,carrier concentration 9.7×1018/cm~3 and 1.3×1019/cm~3,electron mobility 115.7 cm2/Vs and 13 cm2/Vs.They all decrease the carrier concentration,and maintain favorable conductivity.(3)Multi-factors modulation:via modulating one to four factors,we prepared four samples.The result show:the transmittance are from 85%increase to 89%,resistivity maintain<10-3?·cm the carrier concentration decrease obviously,the lowest is 2.4×1016/cm~3,and it 207 cm2/Vs.The result of modulating show:make slow the deposition rate of first thin film,and faster the deposition rate of second thin film,will help attain the effective modulating.The innerstress is reduced after modulating,promoting crystal quality of thin films.The change in nature of stress from compressive to tensile with increasing the number of modulating factors,structure change will be more complex.2?ZnO thin film doped with Na-Mg was prepared by sol-gel method on glass substrate.The effect of ZnO thin film on crystal microstructure,surface topography and optical property was studied on the condition of fixing Na content and changing the Mg content.ZnO thin films have the highest quality and the thin film transmittance reach 88%when the content ratio was 1:1.The result also showed the forbidden bandwidth are enlarged gradually.3?Mg-Sn co-doped ZnO thin films were prepared on quartz glass substrate with different number of spin by sol-gel spin coating.With the number of spin increased,the crystalline quality of the films and the size of ZnO particle improved obviously.The intrinsic luminescence intensity of films increased with the number of spin increasing,and all films appeared strong ultraviolet photoluminescence peak and blue photoluminescence peak.The electrical resistivity was decrease gradually with the film increasing number of spin,and the lowest resistivity reached 2.6×10-3?·cm.The average transmittance of all were about 90%.