Defect-free ZnO nanorods with high angular distribution for enhanced excitonic emission

Low-temperature hydrothermal growth has emerged as a popular method for the fabrication of ZnO nanorods (NRs), increasing the functionality and utility of ZnO-based devices. In this work, we study the influence of growth time, temperature and seed layer on the dimensions and angular distribution of ZnO NRs. High-quality NRs with a crisscrossed 60 degrees angular distribution have been grown with a 20-60 nm diameter and 600 nm length. We show that, within the ideal range of growth parameters, the growth time and temperature have no controllable influence on NR diameter and length, while the deposition method and size of the pre-growth deposited ZnO seeds affects diameter and NR angular alignment. We demonstrate advantages of using crisscross-aligned NRs over planar ZnO for the enhancement of ZnO excitonic emission by optical coupling with gold nanoparticles. These results can be readily adapted for applications that involve surface coating-mediated enhancement of both light emission and injection.

Automated summary

Low-temperature hydrothermal growth is a popular method for fabricating ZnO nanorods (NRs) with enhanced functionality. This study examines the influence of growth time, temperature, and seed layer on the dimensions and angular distribution of ZnO NRs. The results show that growth time and temperature do not have a controllable impact on NR diameter and length, while the deposition method and size of pre-growth deposited ZnO seeds affect diameter and NR angular alignment. The advantages of using crisscross-aligned NRs over planar ZnO for enhancing ZnO excitonic emission are demonstrated.