热蒸发法Zn／ZnO叶状微米结构自组装生长及其发光特性

采用热蒸发法在ZnO缓冲层覆盖着Si衬底上合成了2D叶状的Zn晶枝结构,Zn的晶枝长度约为几十微米,厚度约为200nm,随后Zn晶枝在O2的气氛下热处理,在晶枝表面获得纤细、均匀的ZnO纳米线。晶枝按照无催化、自组装、汽相生长模式生长,晶枝最快生长方向是沿着载气气流的方向释放凝固潜热,XRD分析结果结果显示了Zn纳米线具有六角纤锌矿结构,Zn/ZnO的发光谱显示,在380nm处有一弱的UV近带边发射和中心在505nm处的强绿光发射,绿光发射归因于施主/受主对之间的辐射跃迁。

Self-assembled Growth and Photoluminescence of Leaf-like Zn/ZnO Microstructure by Thermal Evaporation Method

The novel 2D leaf-like zinc dendritic structures have been synthesized on ZnO buffer layer coated onto Si substrates.The growth process is described as free-catalyst,self-assembly and vapor-solid growth mode.The length of the Zn dendrite is about dozens of micrometers and its thickness is about 200 nm.The fastest growth direction of the dendrites is along the carrier gases downstream direction to release the latent heat of solidification.After the zinc dendrites have the thermal process in oxygen ambient,the slim and uniform ZnO nanowires are grown on the surface of Zn dendrites.The results of XRD analysis indicated that the ZnO nanowires are with a hexagonal wurtzite structure.The growth mechanisms of Zn/ZnO structures were investigated.The PL spectrum of Zn/ZnO dendritic structures shown that a weak UV near-band-edge emission is at 380 nm and a strong green emission is centered at 505 nm.The green emission is attributed to radiation transition of donor-acceptor pair.