Ag 중간층 두께에 따른 ZnO 박막의 광학적, 전기적 특성 연구

Abstract

ZnO single layer (60 nm thick) and ZnO with Ag interlayer (ZnO/Ag/ZnO; ZAZ) films were deposited on the glass substrates by using radio frequency (RF) and direct current (DC) magnetron sputter to evaluate the effectiveness of Ag interlayer on the optical visible transmittance and the conductivity of the films. In the ZAZ films, the thickness of ZnO layers was kept at 30 nm, while the Ag thickness was varied as 5, 10, 15 and 20 nm. In X-ray diffraction (XRD) analysis, ZnO films show the (002) diffraction peak and ZAZ films also show the weak ZnO (002) peak and Ag (111) diffraction peak. As a thickness of Ag interlayer increased to 20nm, the grain size of the Ag films enlarged to 11.42 nm and the optical band gap also increased from 4.15 to 4.22 eV with carrier concentration increasing from 4.9 to 10.5×1021 cm-3. In figure of merit measurements, the ZAZ films with a 10 nm thick Ag interlayer showed the higher figure of merit of 4.0×10-3 Ω-1 than the ZnO single layer and another ZAZ films. From the experimental result, it is assumed that the Ag interlayer enhanced effectively the opto-electrical performance of the ZAZ films.