Characteristics of IZO/AZO and AZO/IZO Bi-layer transparent conducting thin films prepared by using PLD

AZO/IZO and IZO/AZO bi-layer thin films were deposited on the glass substrates by using pulsed laser deposition (PLD). The crystallinity and the texture of the thin film depend on the sequence of deposition of the IZO layer and the AZO layer. The crystal structures, the electrical and optical properties of the AZO/IZO and the IZO/AZO thin film were analyzed and compared using X-ray diffraction, field-emission scanning electron microscope, Hall measurements and UV spectrometry. The IZO/AZO bi-layer thin film showed a highly-oriented texture of IZO along the aOE (c) 111 > axis, which implied that the c-axis-oriented AZO buffer layer enhanced the tendency of the IZO thin film to grow preferentially along the aOE (c) 111 > axis. On the other hand, the AZO/IZO thin film did not revealed oriented grain growth of the AZO layer, which indicated that randomly-oriented IZO buffer layer suppressed the tendency of the AZO thin film to grow preferentially along the c-axis. The AZO/IZO and the IZO/AZO bi-layer thin films showed the average values of the AZO and the IZO monolayers for the electrical resistivity and the optical band gap.