Jara Cesar, Rauch Tomáš, Botti Silvana, Marques Miguel A L, Norambuena Ariel, Coto Raul, Castellanos-Águila J E, Maze Jeronimo R, Munoz Francisco
LAAS-CNRS, Université de Toulouse, CNRS, 31031 Toulouse, France.
Institut für Festkörpertheorie und -Optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany.
J Phys Chem A. 2021 Feb 18;125(6):1325-1335. doi: 10.1021/acs.jpca.0c07339. Epub 2021 Feb 7.
A recent study associates carbon with single photon emitters (SPEs) in hexagonal boron nitride (h-BN). This observation, together with the high mobility of carbon in h-BN, suggests the existence of SPEs based on carbon clusters. Here, by means of density functional theory calculations, we studied clusters of substitutional carbon atoms up to tetramers in h-BN. Two different conformations of neutral carbon trimers have zero-point line energies and shifts of the phonon sideband compatible with typical photoluminescence spectra. Moreover, some conformations of two small C clusters next to each other result in photoluminescence spectra similar to those found in the experiments. We also showed that vacancies are unable to reproduce the typical features of the phonon sideband observed in most measurements because of the large spectral weight of low-energy breathing modes, ubiquitous in such defects.
最近的一项研究将碳与六方氮化硼（h-BN）中的单光子发射体（SPEs）联系起来。这一观察结果，连同碳在h-BN中的高迁移率，表明存在基于碳簇的单光子发射体。在此，通过密度泛函理论计算，我们研究了h-BN中多达四聚体的替代碳原子簇。中性碳三聚体的两种不同构象具有零点线能量和声子边带的位移，与典型的光致发光光谱兼容。此外，两个相邻小碳簇的一些构象导致的光致发光光谱与实验中发现的光谱相似。我们还表明，由于在这类缺陷中普遍存在的低能量呼吸模式的大光谱权重，空位无法再现大多数测量中观察到的声子边带的典型特征。
