Layered ZnO microcrystals with intense stimulated emission

Abstract

Hierarchical nanomaterials have shown unprecedented capabilities in emerging technologies ranging from biosensing and solar energy harvesting to photoelectronics. Developing facile routes for the synthesis of functional semiconductors with controllable size, structure, and means of assembly is of significant importance for optimization of nanoscale materials. In this article, layered ZnO crystals are selectively synthesized via a mild pyrolysis route. Ultrafast time-resolved photoluminescence revealed that the confinement effect caused by the microcavity ring within the stacked ZnO nanodisks resulted in spontaneously stimulated emissions showing rapidly shortened lifetime with obvious lasing threshold. A plate-to-column growth mechanism was effective in explaining the possibility of synthesis of some other complex ZnO hexagonal nanostructures. Various synthesized nanostructures showed that a rational variation of preparative parameters might allow for the tailoring of interesting ZnO nanocrystals with a desired morphology even at ambient temperature.