Abstract
Highly crystalline aligned javelin-like ZnO nanorods have been synthesized, for the first time, by thermal evaporation method. The as-grown nanorods have been made by the assembling of two pieces of ZnO nanorods, i.e. hexagonal-shaped nanorods and inverted nanocones which are connected to each other in such a manner that the shaft of the nanocones is attached to the upper portion of the hexagonal nanorod and forms a javelin-like ZnO nanorod. Most importantly, the as-grown nanorods exhibit only a sharp and strong UV emission at 381
nm, confirming an excellent optical property and showing excellent photoluminescent application potential.
Ultraviolet-emitting, single-crystalline aligned javelin-like zinc oxide (ZnO) nanorods were synthesized on copper foil by thermal evaporation at low temperature of 500
°C without catalysts or additives. Detailed structural characterizations confirmed that the formed products are single-crystalline, they possess a wurtzite hexagonal phase and are grown along the
c-axis direction. Raman-active optical-phonon E
2 mode at 437
cm
−1 with sharp and strong UV emission at 381
nm in room-temperature photoluminescence spectrum showed that the obtained ZnO nanorods have a good crystal quality with excellent optical properties. Moreover, a detailed growth mechanism was proposed for the formation of the javelin-like ZnO nanorods.