Investigation of hydrothermally-produced ZnO nanorods and the mechanisms of Li incorporation as a possible dopant

• Published in: Micro and Nano Engineering Vol. 23; p. 100260
• Main Authors: Papageorgiou, Georgios P., Boukos, Nikolaos, Androulidaki, Maria, Christofilos, Dimitrios, Psycharis, Vassilis, Katsikini, Maria, Pinakidou, Fani, Paloura, Eleni C., Krontiras, Christoforos, Makarona, Eleni
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2024; Elsevier
• Subjects: EXAFS; Hydrothermal growth; Li-doping; Photolouminescence; Point defects; Raman spectroscopy; XRD; ZnO nanorods; ZnO nanorods; Hydrothermal growth; Photolouminescence; Point defects; Li-doping; XRD; Raman spectroscopy; EXAFS
• ISSN: 2590-0072; 2590-0072
• DOI: 10.1016/j.mne.2024.100260

Zinc oxide (ZnO) has emerged as one of the most promising candidates for mass-producing cost-efficient optoelectronic devices. This is primarily because it can be synthesized in high-quality nanostructures on a wide range of substrates through relatively simple chemical methods. However, producing p-type ZnO, regardless of the chosen method, remains an open and controversial issue. In this work, Li-doped ZnO nanostructures of varying Li-cocnentration were produced via a two-step hydrothermal growth synthesis and an in-depth analysis based on with Field Emission Scanning Electron Microscopy (FE-SEM), X-ray diffraction (XRD), Raman Spectroscopy, Extended X-Ray Absorption Fine Structure (EXAFS) Spectroscopy, and temperature-dependent Photoluminescence (PL) was carried out in an effort to gain insights into the Li-incorporation mechanisms. The findings indicated a strong interplay between the native defects responsible for the inherent n-type character of the material and Li incorporation. It is suggested that this interplay hinders the successful conversion of the Li-doped nanorods into p-type nanostructures and that when employing the hydrothermal approach it is essential to identify the precise conditions necessary for genuine Li incorporation as a Zn substitutional. [Display omitted] •Hydrothermally-grown ZnO nanorods of various Li concentrations were produced•SEM, Raman Spectroscopy, XRD, EXAFS and temperature-dependent PL were conducted to elucidate the Li incorporation mechanisms•Findings point to an intricate interplay between Li incorporation and point defects during the hydrothermal growth•This intricate interplay hinders successful incorporation of Li atoms as Zinc substitutionals.•Caution is required in selecting the parameters of the hydrothermal growth, which might not lead to successful Li incorporation.