ZnO辐射微米球和微米带梳的特征及生长机理 Growth Mechanism and Characterization of ZnO Radial Microspheres and Comb-Like Microbelts

采用化学气相沉积法成功制备出具有特殊形貌的ZnO辐射微米球以及微米带梳，并对其生长机理进行了研究。合成的ZnO样品是六方纤锌矿结构，其中，ZnO辐射微米球通过两步生长，先成核，后生长纳米线，通过实验发现辐射球状结构的形成关键步骤是在通入氧气之前形成Zn液滴。而微米带梳的生长是通过VS机制先形成微米带，一侧的纳米带阵列通过自催化生长平行于(0001)极性面形成。通过光致荧光谱测试，本文发现室温光致发光峰位于~390 nm和~495 nm处，分别对应紫外和绿光发射峰。 ZnO radial microspheres and comb-like microbelts were synthesized by Chemical Vapor Deposition (CVD). The synthesized ZnO products are hexagonal wurtzite structured. The formation of ZnO radial microspheres follows a two-step process: one is nucleation and another is growth. It is found that the formation of the sphere-shaped liquid Zn droplets before adding oxygen is a key factor to control the morphology of the ZnO radial microspheres. The formation of the comb-like microbelts follows the process: the microbelt is formed by a vapor-solid (VS) growth mechanism firstly, and then the nanobelts on one side are grown by a self-catalysis growth paralleling to the (0001) polar surface. Photoluminescence (PL) spectrum shows two typical emission peaks at ~390 nm and at ~495 nm which were assigned to UV emission and green emission, respectively.