直流反应磁控溅射制备Zn_(1-x)Cd_xO薄膜的结构和光学性能研究

利用直流反应磁控溅射的方法在玻璃衬底上沉积了(002)方向高度择优生长的纤锌矿结构的Zn1-xCdxO(x=0,0.2)合金薄膜.利用XRD、XPS、TEM、PL对薄膜的结构和光学性能进行了详细研究.结果表明,随着x=0到x=0.2,(002)衍射峰从34.36°偏移到33.38°,(002)方向的晶面间距从0.260 nm增加到0.268 nm,Zn1-xCdxO薄膜的光学带隙也从3.20 eV减小到2.70 eV,相应的近带边发光峰从393 nm红移到467 nm.另外,我们还从能带结构观点对Zn1-xCdxO薄膜的发光机理进行了研究.

Structure and Optical Properties of Zn 1-x CdxO Thin Films Synthesized by the dc Reactive Magnetron Sputtering

The ternary Zn1-x Cdx O（ x = 0,0. 2）thin films with wurtzite structure and highly（002）-preferred orientations were deposited on glass substrates by the direct current（dc）reactive magnetron sputtering method. The X-ray diffraction（ XRD）,X-ray photoelectron spectroscopy（ XPS）,transmission electron microscopy （TEM）,optical absorption spectra and photoluminescence（PL）were employed to investigate the structural and the optical properties in detail. Results indicated that as x varies from x = 0 to 0. 2,the diffraction angle of the （002）peaks decreased from 34. 36 to 33. 38° and the lattice spacing increased from 0. 260 to 0. 268 nm. Moreover,the optical band-gap of the Zn1-x Cdx O thin films with the wurtzite structure decreased from 3. 20 eV at x = 0 to 2. 70 eV at x = 0. 2. Correspondingly,the near-band-edge emission peak was red-shifted from 393 to 467 nm. In addition,the PL mechanism of the Zn1-x Cdx O alloy films was discussed in detail from the viewpoint of band structure.