高温高压氮掺杂金刚石的光致发光研究

Photoluminescence Studies on Nitrogen Doped Diamond Synthesized by High Temperature and High Pressure Method

本文利用激光共聚焦显微拉曼光谱仪表征了高温高压法合成的氮掺杂金刚石,并分析了该晶体的光致发光特性。结果表明,金刚石晶体内部含氮量比晶体表面高,且由于氮原子尺寸较大,使得晶体内部应力较高,晶化程度弱化;另外,氮掺杂金刚石的光致发光主要以氮-空位(NV)复合缺陷为主;氮含量高的区域,NV缺陷发光增强,且NV-/NV0强度比也增强。这是因为氮作为施主原子,有利于负电荷缺陷即NV-中心的形成;同时氮含量升高,也会使得费米能级向NV-中心的基态靠近,这也造成了NV-/NV0强度比随氮含量增加而增强。

The nitrogen doped diamond synthesized by high temperature and high pressure method was characterized by micro-Raman spectrometer.It was found that diamond had more nitrogen inside the crystal than the surface,and the larger size of nitrogen atom resulted in the higher stress and weaker crystallization inside the crystal.The photoluminescence of nitrogen-doped diamond was mainly caused by the nitrogen-vacancy(NV)complex.With the increase of nitrogen content,the NV luminescence enhanced together with the increase of intensity ratio of NV^-/NV^0.The reason was that the nitrogen,as the donor atom,favored to the formation of the negative charge defect;besides,the more nitrogen made Fermi level move towards the ground state of NV-center,which also caused the increase of the increase of intensity ratio of NV^-/NV^0.