中文摘要：

以氧化锌（ZnO）粉和碳（C）粉的混合物作为原材料,利用碳热还原的方法合成了六角纤锌矿结构的ZnO微针。用800 nm的近红外激光激发单根微针,在紫外出现两个辐射带,其中一个带的中心波长在392 nm附近,随激发功率的增大略有红移,源自激子-激子散射引起的辐射;另一个带的中心波长大于400 nm,源自电子-空穴等离子体引起的辐射。随着激发功率的增大,在长波长带中产生了激光发射,分析了其发射机理。

英文摘要：

ZnO microneedles with hexagonal wurtzite structure were synthesized by carbon thermal reduction method with the mixture of ZnO powder and graphite powder as source materials.Under excitation of near-infrared laser with 800 nm wavelength,two ultraviolet emission bands were observed from a microneedle.The center of the shorter-wavelength band is located at about 392 nm with a small redshift as excitation power increases,which is attributed to the recombination from exciton-exciton scattering.The center of the longer-wavelength band is larger than 400 nm,which is ascribed to the electron-hole plasma emission.With the excitation power increasing,the laser emission occurs on the longer-wavelength band,and the corresponding positive mechanism was investigated.