Tuning the Surface Morphologies and Properties of ZnO Films by the Design of Interfacial Layer

Nanoscale Research Letters

Yaping Li¹  Hui-Qiong Wang¹  Huahan Zhan¹  Yinghui Zhou¹  Xiaohang Chen¹  Wei Geng¹  Dingqu Lin¹  Junyong Kang¹  Damin Du¹  Hua Zhou¹ 

[1] Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University;

关键词: ZnO;    Surface morphology;    Initial growth;    MBE;    RHEED;    XRD;   

DOI  :  10.1186/s11671-017-2301-8

来源: DOAJ

【 摘 要 】

Abstract Wurtzite ZnO films were grown on MgO(111) substrates by plasma-assisted molecular beam epitaxy (MBE). Different initial growth conditions were designed to monitor the film quality. All the grown ZnO films show highly (0001)-oriented textures without in-plane rotation, as illustrated by in situ reflection high-energy electron diffraction (RHEED) and ex situ X-ray diffraction (XRD). As demonstrated by atomic force microscopy (AFM) images, “ridge-like” and “particle-like” surface morphologies are observed for the ZnO films grown in a molecular O2 atmosphere with and without an initial deposition of Zn adatoms, respectively, before ZnO growth with oxygen plasma. This artificially designed interfacial layer deeply influences the final surface morphology and optical properties of the ZnO film. From room-temperature photoluminescence (PL) measurements, a strong defect-related green luminescence band appears for the ZnO film with a “particle-like” morphology but was hardly observed in the films with flat “ridge-like” surface morphologies. Our work suggests that the ZnO crystallinity can be improved and defect luminescence can be reduced by designing interfacial layers between substrates and epilayers.

【 授权许可】

Unknown