金刚石氮-空位缺陷发光的温度依赖性

Temperature dependence of nitrogen-vacancy optical center in diamond

利用低温光致发光光谱研究了金刚石氮-空位(NV)缺陷发光对测试温度的依赖性,并利用电子-声子耦合理论研究了NV缺陷零声子线的增宽机制.结果表明,随着测试温度的升高,NV缺陷零声子线发生位置红移、强度减弱、半高宽增加的现象,这些可以归因于金刚石晶格膨胀与电子-声子耦合协同作用.在波动场的作用下,NV缺陷零声子线呈现明显的均匀增宽机制.

Diamond,a wide band gap semiconductor material,has been attracting interest in several fields from electrics and optics to biomedicine and quantum computing due to its outstanding properties.These properties of diamond are related to its unique lattice and optically active defect centers.In this paper,the dependence of nitrogen-vacancy(NV)center on measurement temperature is studied by using the low-temperature photoluminescence(PL)spectroscopy in a temperature range of 80–200 K.The results show that with the increase of the measurement temperature,the zero phonon lines of NV defects are red-shifted,its intensity decreases and its full width at half maximum increases.These results are attributed to the synergetic process of the lattice expansion and quadratic electron-phonon coupling.The NV—and NV0 centers have similar values in the quenching activation energy and the thermal softening coefficient,resulting from their similar structures.The small differences may be associated with the electron-phonon coupling.The broadening mechanism of the NV centers is carefully distinguished by T3,T5,T7 that the full width at half maximum of the Gaussian component of NV-and NV0 centers are randomly distributed near 0.1 meV and 2.1 meV,respectively,while the full width at half maximum of the Lorentz component of NV-and NV0 centers increase with measurement temperature increasing.The full width at half maximum of Lorentz of NV-and NV0 centers conform to the T3 relationship.It can be proved that under the action of the fluctuating field,the zero phonon lines of the NV defects exhibit an obvious homogeneous widening mechanism.