Dutta Avisek, Almutairi Amani Saleh, Joseph Jojo P, Baev Alexander, Petrou Athos, Zeng Hao, Prasad Paras N
Department of Chemistry and The Institute for Lasers, Photonics and Biophotonics, University at Buffalo, Suny, Buffalo, NY 14260, USA.
Department of Physics, University at Buffalo, Suny, Buffalo, NY 14260, USA.
Nanophotonics. 2022 Oct 7;11(22):5143-5152. doi: 10.1515/nanoph-2022-0503. eCollection 2022 Dec.
Transition-metal-doped semiconductor nanocrystals have received significant attention because of their attractive features deeming them invaluable in various technological fields including optoelectronics, bio-photonics, and energy conversion, to name a few. Of particular, these interests are two-dimensional materials with useful optical and magnetic properties combined with their large surface areas opening up new applications in biotechnology. These applications range from multimodal optical and magnetic bioimaging and sensing to measuring the weak magnetic field due to brain waves using their magneto-optic properties stemming from the exchange interaction between the transition metal dopants and the carrier spins. These magnetic 2D materials could also significantly advance the field of spintronics. In this work, we report on a study of the magnetic and magneto-optic properties of colloidal two-dimensional (2D) copper-doped CdSe nanoplatelets (NPLs) that are synthesized using a high-temperature colloidal technique. We carried out optical and circularly polarized magneto-photoluminescence spectrometry to investigate the magnetism in our solution-processed nanostructures doped with copper ion impurities. At cryogenic temperatures, two excitonic features are observed for doped NPLs, which are more prominent compared to the undoped NPLs. Furthermore, the excitonic circular polarization (CP) is recorded as a function of the applied magnetic field () and temperature (). The detailed analysis provides a picture of the magneto-optical behavior of the doped 2D NPLs in the presence of paramagnetic copper ions. This work paves the way for significant advances in bio/nanophotonics where tunable optical and magnetic properties of doped nanoplatelets can be leveraged to make more efficient, flexible, and low-cost devices.
过渡金属掺杂的半导体纳米晶体因其具有吸引力的特性而备受关注，这些特性使其在包括光电子学、生物光子学和能量转换等多个技术领域具有极高价值。特别值得一提的是，二维材料兼具有用的光学和磁性特性，且具有较大的表面积，这为生物技术领域开辟了新的应用。这些应用涵盖多模态光学和磁性生物成像与传感，以及利用过渡金属掺杂剂与载流子自旋之间的交换相互作用所产生的磁光特性来测量脑电波引起的弱磁场。这些磁性二维材料还可能极大地推动自旋电子学领域的发展。在这项工作中，我们报告了对采用高温胶体技术合成的胶体二维（2D）铜掺杂硒化镉纳米片（NPLs）的磁性和磁光特性的研究。我们进行了光学和圆偏振磁光致发光光谱分析，以研究我们的溶液处理的掺杂铜离子杂质的纳米结构中的磁性。在低温下，掺杂的NPLs观察到两个激子特征，与未掺杂的NPLs相比更为显著。此外，记录了激子圆偏振（CP）随外加磁场（）和温度（）的变化。详细分析提供了在顺磁性铜离子存在下掺杂的二维NPLs的磁光行为图景。这项工作为生物/纳米光子学的重大进展铺平了道路，在该领域中，可以利用掺杂纳米片可调的光学和磁性特性来制造更高效、灵活和低成本的器件。
