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通过溶液法合成了Cu掺杂ZnO量子点。X射线衍射(XRD)和高分辨电子透射电镜(HRTEM)图像显示Cu掺杂ZnO量子点具有六角纤锌矿结构,晶粒大小为4～5nm。Cu掺杂抑制了ZnO量子点颗粒长大。室温光致发光(PL)谱观察到紫外带边和可见区两个发射峰。随着Cu掺杂浓度的增大,紫外荧光峰位发生缓慢红移,由366nm移到370nm;可见区发射峰位发生蓝移,由525nm移到495nm;同时,两个发射峰强度降低。光谱结果表明:Cu的掺入,一方面抑制表面与O空位有关的缺陷,在495nm出现了与Cu1+有关的发射峰;另一方面,Cu离子掺入ZnO量子点引入一些非辐射中心,降低了自由激子发射。
Cu doped ZnO quantum dots were synthesized by solution method. X-ray diffraction (XRD) and high-resolution electron transmission electron microscopy (HRTEM) images show that Cu-doped ZnO quantum dots have a hexagonal wurtzite structure with a grain size of 4 to 5 nm. Cu doping inhibits ZnO quantum dot particle growth. At room temperature photoluminescence (PL) spectra, two emission peaks of UV band edge and visible region were observed. With the increase of Cu doping concentration, the UV fluorescence peak shifts slowly from 366nm to 370nm. The emission peak shifts to blue light from 525nm to 495nm. At the same time, the intensities of the two emission peaks decrease. The results show that the incorporation of Cu, on the one hand, inhibits the defect associated with O vacancies on the surface and the emission peak at 495nm related to Cu1 +. On the other hand, Cu ion incorporates ZnO quantum dots to introduce some non-radiative centers, Free exciton emission.