Presentation Information
[9a-PA1-13]Control of Site-Selective ZnO Nanowire Growth via Zn-PEI Dynamic Buffering
〇Haruka Honda1, Tsunaki Takahashi1, Yoshiaki Daigo2, Shinichi Tanabe2, Mitsuaki Iwashita2, Takeshi Yanagida1 (1.The Univ. of Tokyo, 2.Tokyo electron)
Keywords:
nanowire,ZnO,hydrothermal growth
Polyethyleneimine (PEI) is widely used as an additive to suppress radial growth during the hydrothermal synthesis of ZnO nanowires. This effect has often been explained by adsorption of PEI on the m-plane sidewalls of ZnO. However, this surface-adsorption model mainly describes growth after sidewall formation and does not fully explain how PEI affects the early stages of nucleation and morphology control. In this study, site-selective ZnO nanowires were grown on nanopatterned ZnO single-crystal substrates by hydrothermal synthesis using zinc nitrate and hexamethylenetetramine. The effects of PEI addition, molecular weight, and mixed-PEI conditions were investigated by SEM. PEI suppressed the variation in initial nucleus growth, indicating that it affects the growth process before well-defined sidewalls are formed. AES showed no clear nitrogen signal from PEI on the final nanowire surface, whereas ATR-FTIR suggested Zn–PEI complex formation. These results indicate that PEI can act not only as a sidewall adsorbent but also as a dynamic buffer that controls Zn2+ supply in solution. Mixed PEI enabled the growth of fine and uniform ZnO nanowires.