Epitaxial growth and electronic structure of a layered zinc pnictide semiconductor, β-BaZn2As2

THIN SOLID FILMS

卷:559

Article; Proceedings Paper

Xiao, Zewen¹  Ran, Fan-Yong¹  Hiramatsu, Hidenori^1,2  Matsuishi, Satoru²  Hosono, Hideo^1,2,3  Kamiya, Toshio^1,2 

[1] Tokyo Inst Technol, Mat & Struct Lab, Midori Ku, Yokohama, Kanagawa 2268503, Japan

[2] Tokyo Inst Technol, Mat Res Ctr Element Strategy, Midori Ku, Yokohama, Kanagawa 2268503, Japan

[3] Tokyo Inst Technol, Frontier Res Ctr, Midori Ku, Yokohama, Kanagawa 2268503, Japan

关键词: Zinc pnictide;    Epitaxial growth;    Layered structure;    Band gap;    Hybrid functional calculation;   

DOI  :  10.1016/j.tsf.2013.10.135

来源: Elsevier

【 摘 要 】

BaZn2As2 is expected for a good p-type semiconductor and has two crystalline phases of an orthorhombic alpha phase and a higher-symmetry tetragonal beta phase. Here, we report that high-quality epitaxial films of the tetragonal beta-BaZn2As2 were grown on single-crystal MgO (001) substrates by a reactive solid-phase epitaxy technique. Out-of-plane and in-plane epitaxial relationships between the film and the substrate were BaZn2As2 (001)//MgO (001) and BaZn2As2 [200]//MgO [200], respectively. The full-widths at halfmaximumwere 0.082 degrees for a 008 out-of- plane rocking curve and 0.342 degrees for a 200 in-plane rocking curve. A step-and-terrace structure was observed by atomic force microscopy. The band gap of beta-BaZn2As2 was evaluated to be around 0.2 eV, which is much smaller than that of a family compound LaZnOAs (1.5 eV). Density functional theory calculation using the Heyd-Scuseria-Ernzerhof hybrid functionals supports the small band gap. (C) 2013 Elsevier B. V. All rights reserved.

【 授权许可】

Free