Aluminum-doped zinc oxide (AZO) thin films incorporated with multi-walled carbon nanotubes (MWCNTs) have been prepared by sol-gel technique on glass substrates. The ratio of the MWCNT in sol-gel solution ranges from 0.01 to 1.0 wt.%. This study investigates the effects of MWCNT ratio on structural, electrical, and optical properties of AZO:MWCNT thin films. The XRD analysis showed a strong (0 0 2) peak along the c axis at 2θ ~ 34.4 o indicating a hexagonal wurtzite structure for the AZO:MWCNT thin films. The intensity of (0 0 2) peak decreased with the increasing MWCNT ratio, revealing that AZO were bounding with the MWCNTs. The sheet resistance of AZO:MWCNT thin films significantly decreased from 1.38 × 104 to 10.5 Ω/□ with increasing the MWCNT ratio from 0.01 to 1.0 wt.%; meanwhile, the optical transmittance in the visible wavelength region decreased from 87.9% to 12.1%, respectively. The figure of merit showed that the developed AZO:MWCNT thin film with the MWCNT ratio of 0.01 wt.% has the optimal electro-optical properties for transparent conducting electrode applications.
Keywords: Transparent conducting oxide (TCO), Zinc oxide (ZnO), Carbon nanotube (CNT), Sol-gel, Spin coating.