Tuning spin–orbit coupling in (6,5) single-walled carbon nanotube doped with sp3 defects
Tuning spin–orbit coupling in (6,5) single-walled carbon nanotube doped with sp3 defects
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DOI：
10.1063/5.0031337
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发表时间：
2021-01
影响因子：
3.2
通讯作者：
K. Trerayapiwat;S. Lohmann;Xuedan Ma;S. Sharifzadeh
中科院分区：
文献类型：
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作者：
K. Trerayapiwat;S. Lohmann;Xuedan Ma;S. Sharifzadeh
含缺陷的单壁碳纳米管具有明亮的光致发光和单光子发射，是一类很有前途的光电材料。使用密度泛函理论模拟，辅以测量，我们调查的电子结构的一系列量子缺陷连接到（6，5）单壁碳纳米管的目标调整的自旋轨道耦合的缺陷结构中引入一个重原子。我们表征的基态电子和自旋性质的四个合成和三个潜在的缺陷管，并发现所有的合成缺陷考虑引入一个本地化的midgap缺陷为中心的状态，包含一个单一的电子，<$0.2 -0.3 eV以上的价带。的自旋密度是位于s p 3缺陷的网站，可以忽略不计的自旋轨道耦合，甚至与存在的Pd原子。通过计算测试了三个额外的官能团，以增加金属附近的自旋局域化，从而增加自旋轨道耦合。我们预测，只有氯二膦钯（II）- [Cl（PH 3）2 Pd（II）-]缺陷的结果在增加的自旋轨道分裂的缺陷状态和导带与ristine样的单壁碳纳米管，激发态跃迁的自旋轨道耦合的措施。这项研究表明，在（6，5）单壁碳纳米管的未钝化的sp 3缺陷，形成一个重原子和sp 3碳之间的直接键允许调谐的自旋轨道耦合。
Single-walled carbon nanotubes (SWCNTs) containing s p 3 defects are a promising class of optoelectronic materials with bright photoluminescence and demonstrated single-photon emission. Using density functional theory simulations, complemented by measurements, we investigate the electronic structure of a series of quantum defects attached to (6,5) SWCNT with the goal of tuning the spin–orbit coupling by introduction of a heavy atom in the defect structure. We characterize the ground state electronic and spin properties of four synthesized and three potential defects on the tube and find that all of the synthesized defects considered introduce a localized midgap defect-centered state containing a single electron, ≈ 0.2–0.3 eV above the valence band. The spin density is located at the s p 3 defect site with negligible spin–orbit coupling even with the presence of a Pd atom. Three additional functional groups were tested via computation to increase spin localization near the metal, thereby increasing spin–orbit coupling. We predict that only the chlorodiphosphanepalladium(II)– [Cl(PH 3) 2Pd(II)–] defect results in increased spin–orbit splitting of the defect state and the conduction band associated with the pristine-like SWCNT, a measure of the spin–orbit coupling of excited state transitions. This study suggests that for unpassivated s p 3 defects in (6,5) SWCNT, forming a direct bond between a heavy atom and the s p 3 carbon allows for tuning of spin–orbit coupling.