Vertically Aligned Ultraslim ZnO Nanowires Formed by Homobuffer: Growth Evolution and Emission Properties

Vertically aligned, ultraslim ZnO nanowire arrays, ≤ 10 nm in diameter, were fabricated by depositing a homobuffer layer on a Si substrate by metalorganic chemical vapor deposition and their growth mechanism was examined. During the heating process, the side facet planes of the nanosheets were transformed from high index planes, such as (011̅3) and (011̅2), to low index planes, such as (011̅1) and (011̅0), which is related to the available surface energy during growth. The ultraslim nanowires exhibited extremely intense ultraviolet emission with enhanced thermal activation energy in the photoluminescence measurements as well as excellent field-emission performance with intense brightness and a low turn-on field. This extraordinary emission performance of the ultraslim ZnO nanowires was attributed to the concurrent achievement of high crystalline quality and the vertical alignment of the ultraslim nanowires with the appropriate density at high temperatures.