Studies On Properties Of W Doping ZnO Transparent Conductive Oxide Thin Films Prepared By RF Magnetron Sputering

Transparent conductive oxide thin film have been used widely in photoelectric products—Solar cell front electrode,liquid crystal display,touch control LCD,protection glasses possess radioresistance and high transparent,heating circuit in front windscreen and so on.It's a critical material in photoelectric products,and it is a urgent and common research problem need to be resolved.By far,three fundamental key problems--the re-strictive relation between conductive and transmittance in near infrared region,crater shape surface prepared directly and contact barrier between ZnO-TCO and p-SiC:H window layer,which exist in the ZnO-TCO thin film applied in solar cell as front elec-trode yet to be resolved.In order to solve the two problems--the restrictive relation between conductive and transmittance in near infrared region,and crater shape surface prepared directly.In the thesis,We have tried to use radio-frequency magnetron sputtering,through W doping,and suggest adopt growth in stages model—"ZnO:W layer + transition layer + texture morphology directly".And explore the influence mechanism of growth factors in differ-ent growth stage.1.By means of ZnO:W layer growth orthogonal experiment and compare with ZnO layer,researches show that:1)The resistivity and transmittance in 400?2500nm wavelength of ZnO:W thin film layer under the optimal parameter are 3.97×10-5?·cm and 86.7%;2)The primary and secondary growth factor of ZnO:W layer are:distance between target and substrate,growth temperature,sputtering power,sputtering pressure and gas flow in sequencely;3)The optimum level of corresponding factors are:51mm?RT?200W?1pa and 30sccm;4)The analysis of XRD and XPS of ZnO:W thin film show that W6+ replace Zn2+ effec-tively,achieve efficient doping.2.Base on ZnO:W thin film layer growth orthogonal experiment result,we try to explore the inner mechanism of growth factors affect ZnO:W layer,and results show that:1)The weakening of W doping effect is the primary cause of electrical performance degradation with the distance between target and substrate increasing;2)Depositing ZnO:W thin film layer under room temperature is optimum;3)When sputtering power is greater than 200W,it is easy to produce high energy atomic oxygen anions,and the atomic oxygen anions will inject in the ZnO:W layer forming acceptor,leading com-pensation and thus result in carrier concentration dropping.Meanwhile,the grain size will decrease for the increasing deposition rate with the sputtering power increasing;4)Plasma density and mean free path of sputtering particles have play an important role in W doping effect and surface morphology of ZnO:W layer;5)Although inlet moderate oxygen can improve crystallization property and optical transmittance,however the con-ductivity will drop remarkable for W will easily generate WO3 in the active oxygen atoms atmosphere.So it is improper for growth ZnO:W thin film layer in the oxygen atmosphere.3.Explore the growth of transition layer,we found that:1)Sputtering power,the distance between substrate and target and the growth tem-perature have great influence in the kinetic energy and kinetic energy,while the kinetic energy and kinetic energy will affect the grain size,compactness and W doping effect of transition layer remarkable.Through hydrogen etching the transition layer,the results show that:the transition layer with small grain size and diversity growth orientation is conducive to be etched crater shape surface;2)The optimum level of the distance be-tween substrate and target,sputtering power and growth temperature to growth transition layer are:63mm,300W and 150? respectively.4.The resech for preparing texture structure directly showed that:1)The surface morphology of the best textured ZnO:W-TCO thin film appear ob-vious crater shape surface,and the crater size are uniform,and sheet resistance,resistivi-ty,average transmittance in 400?2500nm wavelength and haze in 550nm wavelength are:0.58?/?,9.38×10-4?·cm,81.98%and 13.16%respectively;2)The primary and second-ary etching factor of preparing crater shape morphology are:distance between target and substrate,sputtering power,hydrogen argon ratio and sputtering pressure,and their cor-responding best level are:51mm?300W?0%and 0.1pa respectively;3)Increasing mean free path of sputtering particles to achieve high energy is the main way to prepare crater shape morphology;4)The stability test show that the best texture ZnO:W-TCO thin film has stable electrical property and still remain good crater shape texture structure in the 300? environment.