Influence of substrate surface energy and surfactant on crystalline morphology and surface defect density in hydrothermally-grown ZnO nanowires. (April 2018)

• Record Type: Journal Article
• Authors: Park, Ji-Sub; Mahmud, Imtiaz; Shin, Young-Chul; Choi, Jun-Chan; Kim, Byeonggon; Shin, Han Jae; Choi, Yoonseuk; Kim, Hak-Rin
• Is Part Of: Materials science in semiconductor processing. Volume 77(2018)
• Page Start: 64
• Page End: 73
• Publication Date: 2018-04
• Subjects: ZnO zinc oxide -- 1D one-dimensional -- NW nanowire -- pH hydrogen exponent -- PEI polyethyleneimine -- UVO ultraviolet ozone -- IPA isopropyl alcohol -- DI deionized -- BOE buffered oxide etch -- Zn(CH3COO)2·2H2O zinc acetate dehydrate -- Zn(NO3)2·6H2O zinc nitrate hexahydrate -- FE-SEM field-emission scanning electron microscopy -- PL photoluminescence -- TR-PL time-resolved PL -- XRD x-ray diffraction -- NH2 amino group -- OH hydroxyl group; ZnO nanowires -- ZnO seed layer -- Surface energy -- Surfactant -- Hydrothermal growth; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2018.01.014
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: We investigated the influence of substrate surface energy before seed layer formation on hydrothermally grown zinc oxide (ZnO) nanowires (NWs). The qualities of ZnO NWs prepared by the surface-enhanced growth method with ultraviolet ozone (UVO) treatment were analyzed in terms of crystalline morphology and surface defect density, and were compared with those of ZnO NWs prepared by the conventional bulk-enhanced growth method adopting polyethyleneimine (PEI) as the surfactant in an aqueous growth solution. In both cases, a positive effect on the morphological properties and crystallinity of ZnO NWs was observed; however, the surface-enhanced growth method was more efficient for obtaining hydrothermally grown ZnO NWs with higher aspect ratios and larger surface areas. The ZnO NW growth rate in the surface-enhanced growth method was two times faster than in the conventional bulk-enhanced growth method. Photoluminescence (PL) spectra and time-resolved PL (TR-PL) responses indicated that a high density of oxygen vacancies on ZnO NW surfaces was produced by the surface-enhanced growth method, because highly oriented ZnO NWs can be grown without surface passivation effect, on the contrary with the bulk-enhanced growth method. Graphical abstract: