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Vol.52, No.4, 271 ~ 277, 2014
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| Title |
| Structural and Optical Characteristics of CdxZn1-xO Thin Films with Various Cd Concentrations Prepared by a Dip-Coating Process |
| 지익수 Ii Ksoo Ji , 박형길 Hyung Gil Park , 김영규 Young Gyu Kim , 김소아람 Soaram Kim , 남기웅 Gi Woong Nam , 김양수 Yang Soo Kim , 임재영 Jae Young Leem |
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| Abstract |
| Ternary CdxZn1-xO thin films are deposited by a sol-gel dip-coating method onto quartz substrates with various amounts of Cd content (x = 0, 0.05, 0.15, and 0.25). The structural and optical properties of the CdxZn1-xO thin films are investigated using x-ray diffraction (XRD), photoluminescence (PL), and (ultravioletvisible) (UV-Vis) spectroscopy. In the XRD patterns, the intensity of the diffraction peaks for ZnO decreases, while the intensity of the diffraction peaks for CdO increases with increases in the Cd content. Above x = 0.15, both diffraction peaks for ZnO and CdO are observed in the XRD pattern, and this indicates that the wurtzite structure for ZnO and the rock-salt structure for CdO coexist in CdZnO thin films. The PL spectra of the films results demonstrate that the near band edge emission peaks in the ultraviolet region shift to lower energy range (red-shift) and the deep level emission peaks at the visible region decreases with increases in the Cd content. The optical properties such as transmittance, optical band gap, and Urbach energy are calculated using the optical data. Using linear fitting of the absorption edge, the band gap energies of the thin films are derived as 3.27, 3.19, 3.12, and 3.03 eV for x = 0, 0.05, 0.15 and 0.25, respectively. In addition, the bowing parameter for the energy band gap of CdxZn1-xO is estimated to be Eg( x) = 3.3 . 1.2 x + x2. |
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| Key Words |
| CdZnO, thin films, sol-gel, x-ray diffraction, optical properties |
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