Strong blue-light emission in the flexible branched nanowire-on-nanowire pristine ZnO organizations constructed by a tandem multiprong growth nanoarchitectures

Abstract

Zinc oxide (ZnO) exhibits an outstanding ability to form a wide range of nano/microstructures. At enhanced environmental temperature (TE = 33.1 C), flexible branched single-crystalline (SC) nanowire-on-nanowire (NW-on-NW) pristine ZnO nanoarchitectures (NAs) have been synthesized for the first time through a simple ambient pressure vapor-phase transport (VPT) process. We proposed that the construction of the spider plant-like ZnO NAs is via a tandem multiprong vapor-solid-solid growth mode using larger gold catalysts instead of the conventional single-prong vapor-liquid-solid growth mechanism. Notably, unlike the previous results of single-component SC ZnO NWs, unexpectedly, the Oxygen-deficient SC NW-on-NW pristine ZnO NAs exhibit a very strong blue-light (BL) solitary emission peak at 494 nm where a self-activated multiphoton process called hierarchical photonic chain reaction (HPCR) mechanism was suggested. Our work enriches the VPT-grown flexible branched SC NW-on-NW pristine ZnO NAs with BL photoluminescence, and provides the first evidence for the multiprong growth that was predicted many years ago.