Insight into the Spin Properties in Undoped and Mn-Doped CdSe/CdS-Seeded Nanorods by Optically Detected Magnetic Resonance
Insight into the Spin Properties in Undoped and Mn-Doped CdSe/CdS-Seeded Nanorods by Optically Detected Magnetic Resonance
复制标题
通过光学检测磁共振深入了解未掺杂和 Mn 掺杂 CdSe/CdS 种子纳米棒的自旋特性
DOI：
10.1021/acsnano.0c05454
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发表时间：
2020
期刊：
影响因子：
17.1
通讯作者：
Lifshitz, Efrat
中科院分区：
文献类型：
--
作者：
Dehnel, Joanna;Barak, Yahel;Meir, Itay;Budniak, Adam K.;Nagvenkar, Anjani P.;Gamelin, Daniel R.;Lifshitz, Efrat
通过磁性掺杂控制半导体纳米结构中光生物种的自旋自由度是一个新兴的科学领域，可能在新的基于自旋的技术的发展中发挥重要作用。目前的工作探讨了自旋性质的胶体CdSe/CdS：Mn种子纳米棒结构中掺杂的Mn 2+离子的稀释浓度横跨棒。自旋性质的测定使用连续波光学检测磁共振（ODMR）光谱记录下可变的微波斩波频率。这些实验使几个不同的辐射复合过程的解卷积：带到带，陷阱到带，和陷阱到陷阱发射。结果揭示了载流子俘获对细长结构自旋性质的主要作用。的磁性参数，确定通过自旋哈密顿模拟的稳态ODMR光谱，反映与种子/棒界面处的载流子捕获的各向异性。这些观察揭示了载流子的g因子和自旋交换耦合常数的变化，以及由于界面载流子和相邻Mn 2+离子之间的磁耦合而导致的辐射和自旋晶格弛豫时间的延长。总的来说，这项工作强调了种子纳米棒中的自旋自由度由界面捕获控制，并且可以通过磁性掺杂进一步操纵。这些结果为与未来基于自旋的技术相关的各向异性纳米结构自旋性质提供了见解。
Controlling the spin degrees of freedom of photogenerated species in semiconductor nanostructuresviamagnetic doping is an emerging scientific field that may play an important role in the development of new spin-based technologies. The current work explores spin properties in colloidal CdSe/CdS:Mn seeded-nanorod structures doped with a dilute concentration of Mn2+ions across the rods. The spin properties were determined usingcontinuous-waveoptically detected magnetic resonance (ODMR) spectroscopy recorded under variable microwave chopping frequencies. These experiments enabled the deconvolution of a few different radiative recombination processes: band-to-band, trap-to-band, and trap-to-trap emission. The results uncovered the major role of carrier trapping on the spin properties of elongated structures. The magnetic parameters, determined through spin-Hamiltonian simulation of the steady-state ODMR spectra, reflect anisotropy associated with carrier trapping at the seed/rod interface. These observations unveiled changes in the carriers’g-factors and spin-exchange coupling constants as well as extension of radiative and spin–lattice relaxation times due to magnetic coupling between interface carriers and neighboring Mn2+ions. Overall, this work highlights that the spin degrees of freedom in seeded nanorods are governed by interfacial trapping and can be further manipulated by magnetic doping. These results provide insights into anisotropic nanostructure spin properties relevant to future spin-based technologies.