Study On The Properties Of Tungsten-doped Indium Oxide Transparent Conductive Films

In₂O₃ is an important optical material for transparent conductive oxide films.Among the known transparent conductive oxides such as ZnO and SnO₂,In₂O₃ has excellent properties such as wide bandgap,low resistivity,high electron mobility and high transmittance in the visible region.Therefore,it is a very important materials in solar cells,transparent thin film transistors,lasers,flat panel displays,light emitting diodes,touch screens,etc.Ultraviolet detectors and electromagnetic shielding protective coatings,but how to improve the performance of transparent conductive oxides has become the direction of scientific researchers in recent years.It is gratifying that a small amount of doping of metal ions can solve this problem to a certain extent.In tungsten-doped In₂O₃ films,because tungsten atoms exist in the form of positive hexavalent high valence ions,In³⁺can be substituted in the lattice during deposition.At the same doping concentration,more free carriers can be obtained for doped oxides because of the difference of valence states between cations.In other words,enough free carriers can be obtained with fewer dopant.Proper doping of metal ions,on the one hand,can obtain enough carriers,improve carrier concentration;on the other hand,can reduce the scattering of charged ions,improve carrier mobility and transmittance,and ultimately obtain transparent conductive oxide films with higher ion mobility and High transmittance.The transparent conductive W-doped In₂O₃ films were prepared by DC magnetron sputtering.The target is In₂O₃ doped with 2%tungsten.The effects of different deposition temperature,film thickness and deposition pressure on the properties of In₂O₃ transparent conductive films were studied.SEM,XRD,four probe detection and Hall Effect testing system were used to characterize.The results are as follows:?1?The optimum growth procedure is obtained through experiments:the deposition pressure is set at 2 Pa,the sputtering power is 100 W,the precess is started by introducing contious flow of Ar at 20 Sccm.The system is pumped down to a pressure of 6×10^-4Pa,and the deposition time was 20 minutes.The resistivity of the prepared IWO films is 0.83×10^-4?cm,the carrier mobility is 38.6cm²V^-1S^-1,the highest transmittance is 93%and the average transmittance is over 80%in the visible range.?2?At the appropriate substrate temperature and process parameters?such as sputtering pressure,argon flow rate,power,deposition time?,sputtering ions can obtain appropriate energy.The film has good crystallinity,compact and uniform grain stacking,and obvious grain boundary.Doped W⁶⁺ions can effectively replace In³⁺ions in In₂O₃ to form n-type semiconductors.Vacancy oxygen and doped ions in the films provide the main free carriers.Low ion scattering results in high carrier concentration,which leads to low resistivity.?3?By XRD and EDS analysis,it was confirmed that the films were pure,complete and uniform.