Structural, morphology and optical properties of Zn_(1-x)Cd_xO solid solution grown on c-plane sapphire substrate

¹ Laboratoire Physico-chimie des Matériaux, Unité de Service Commun de Recherche « High resolution X-ray diffractometer », Département de Physique, Université de Monastir, Faculté des Sciences de Monastir, Avenue de l’Environnement, 5019 Monastir, Tunisia
² Laboratoire Physico-chimie des Matériaux, Département de Physique, Université de Monastir, Faculté des Sciences de Monastir, Avenue de l’Environnement, 5019 Monastir, Tunisia
³ Unité de recherche hétéroepitaxie et ses applications, Département de Physique, Université de Monastir, Faculté des Sciences de Monastir, Avenue de l’Environnement, 5019 Monastir, Tunisia
⁴ Groupe d’Etude de la Matière Condensée, Centre National de la Recherche Scientifique/Université de Versailles Saint Quentin en Yvelines, UMR 8635 Paris France

^a e-mail: Fouzri.Afif@gmail.com

Abstract

Zn_(1-x)Cd_xO solid solutions with a composition ranging from pure ZnO up to x=0.046 have been grown on cplane sapphire substrates by using metal organic chemical vapor deposition (MO-CVD). The lattice deformation, morphology and optical properties of these films were examined in detail using high resolution X-ray diffraction, atomic force microscopy (AFM) and photoluminescence (PL) as Cd incorporation. Our study reveals significant microstructure modification of Zn_(1-x)Cd_xO from x≥0.7% but single phase of wurtzite structure is maintained for all films. The Pl spectra and the band gap of the Zn_(1-x)Cd_xO film show red shift to visible light range which is interpreted in terms of band gap modulation due to Cd incorporation. Increase of Cd content leads to the emission broadening with growing lower energy peak (at 10K) and degraded crystallinity.