Abstract |
Al-doped ZnO (AZO) thin films were deposited on glass substrates by RF-magnetron sputtering and effects of RF-power and O2/Ar gas flow ratio on the electrical and optical properties were investigated. According to XRD analysis results, the FWHM of the ZnO (002) peak tends to increase substantially with increasing the ratio of the RF power for the AZO target to that for the ZnO target for R>1. On the other hand, FWHM is found to be minimal for r = 0.5. AFM analysis results show that the surface roughness increases with R. The lowest roughness is obtained for r = 0.5. According to the Hall measurement results both the carrier concentration and mobility are highest for R = 1.5 and the resistivity is lowest for R = 2.0. In the case of r both the carrier concentration and mobility tends to decrease and the resistivity tends to increase as r increases, which maybe caused by the recombination of electrons due to Al doping and holes due to oxygen atoms. Also, the transmittance of the ZnO film tends to decrease for R<1.5 but to increase for R>1.5. Judging from the above analysis results on the crystallinity, surface roughness resistivity and transmittance of AZO thin films, optimum R and r values are 1.0 and 0.5, respectively. |
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Key Words |
AZO, RF magnetron sputtering, Al doping, O2/Ar flow ratio, Transparent conducting oxides |
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