Structural, Morphological, Optical and Electrical Properties of Zn<sub>(1-x)</sub>Cd<sub>x</sub>O Solid Solution Grown on <i>a</i>- and <i>r</i>-Plane Sapphire Substrate by MOCV

• 作者: Afif Fouzri Al Housseynou Tauré Amor Bchetnia Mohamed Amine Boukadhaba Nawfel Sakly Vincent Sallet
• 来源期刊: 结晶过程及技术期刊(英文)
• 学科: 物理学
• 年，卷（期）: 2013,（1）
• 页码范围: 36-48
• 页数: 13页
• 分类号: O48

摘要

Zn(1-x)CdxO films have been grown on (a-plane) and (r-plane) sapphire substrate by metal organic chemical vapor deposition. A maximum cadmium incorporation of 8.5% and 11.2% has been respectively determined for films deposited on a- and r-plane sapphire. The optical transmission spectra and energy band-gap equation established by Makino et al. were used to estimate the cadmium mole fraction of the solid solutions. Structural, morphological and optical properties of these films were examined using high resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM) and room and low temperature photoluminescence (Pl) as Cd incorporation and employed substrate. X-ray diffraction study revealed that all films had wurtzite phase but solid solution grown on a-plane sapphire are polycrystalline with a preferred orientation along the [0001] direction and a-plane film are epitaxially grown on r-plane sapphire. AFM image show significant differences between morphologies depending on orientation sapphire substrate but no significant differences on surface roughness have been found. The near band-edge photoluminescence emission shifts gradually to lower energies as Cd is incorporated and reaches 2.916 eV for the highest Cd content (11.2%) at low temperature (20 K). The room temperature hall mobility decreases with the Cd incorporation but it is larger for Zn(1-x)CdxO grown on r-plane sapphire.