Articles you may be interested inHigh-temperature lasing characteristics of randomly assembled ZnO nanowires with a ridge waveguideWe report the high-temperature ultraviolet random laser action in ZnO nanoneedles. The characteristic temperature of the ZnO nanoneedle lasers was derived to be 138 K in the temperature range from 300 to 615 K. The cavity length of the random lasers as a function of temperature was determined by Fourier transform spectroscopy. The cavity length decreased with an increase in temperature from ϳ14 m at 300 K to ϳ 2 m at 550 K. The optical gain of the ZnO nanoneedle lasers at high temperature is attributed to a self-compensation mechanism in the cavity length.
An ion-beam technique has been employed to fabricate nanoscale needlelike structures in ZnO thin films on silicon and plastic substrates at room temperature. The ZnO nanoneedles showed a single-crystalline wurtzite structure, the stem of which was around 100nm in diameter. The sharp tips of the nanoneedles exhibited an apex angle of 20° as measured by transmission electron microscopy. Room-temperature ultraviolet random lasing action was observed in the ZnO nanoneedle arrays under 355nm optical excitation.
Zn 1 − x Mg x O nanoneedles were prepared by an ion-beam technique on Zn1−xMgxO thin films with Mg contents of up to 21at.%. The photoluminescence emission energies of the Zn1−xMgxO nanoneedles measured at room temperature increased monotonically with Mg contents and it reached 3.6eV when x=0.21. Random laser action was observed in the Zn1−xMgxO nanoneedles with x⩽0.1 at temperature ranging from 300to470K under 355nm optical excitation. The characteristic temperature of the Zn1−xMgxO nanoneedles was determined to be 84K. The high-temperature lasing of the Zn1−xMgxO nanoneedles are attributed to the high crystal quality of the nanoneedles, enhancement of oscillator strength in nanostructures, and a self-compensation mechanism in random laser cavities.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.