Phase-Engineering-Induced Generation and Control of Highly Anisotropic and Robust Excitons in Few-Layer ReS2.
Phase-Engineering-Induced Generation and Control of Highly Anisotropic and Robust Excitons in Few-Layer ReS2.
复制标题
DOI：
10.1021/acs.jpclett.7b01029
复制
发表时间：
2017-06
期刊：
影响因子：
--
通讯作者：
Shuyi Wu;Y. Shan;Junhong Guo;Lizhe Liu;Xiaoxu Liu;Xiaobing Zhu;Jinlei Zhang;Jiancang Shen
中科院分区：
文献类型：
--
作者：
Shuyi Wu;Y. Shan;Junhong Guo;Lizhe Liu;Xiaoxu Liu;Xiaobing Zhu;Jinlei Zhang;Jiancang Shen
二维材料中由自旋轨道耦合或各向异性空间限制引起的各向异性激子行为已经在成像应用中被利用。在这里，我们提出了一种新的策略，产生高能量和强大的各向异性激子在少层硫化铼纳米片相工程。这种方法克服了由层厚度施加的限制，使得能够在室温下产生可见的偏振光致发光。超声波化学剥离的实施，以引入金属T相的ReS 2的少层半导体Td纳米片。在这种配置中，光激发可以很容易地产生“热”电子，通过金属-半导体界面隧穿到Td相，以增强波函数和屏蔽库仑相互作用之间的重叠。由于强的电子-空穴相互作用，观察到光学带隙的显著增加。产生具有可见光发射（1.5-2.25 eV）的高度各向异性和紧密结合的激子，并且可以通过定制T相浓度来控制。这种新的策略允许操作偏振光学信息，并在光电器件中具有很大的潜力。
The anisotropic exciton behavior in two-dimensional materials induced by spin-orbit coupling or anisotropic spatial confinement has been exploited in imaging applications. Herein, we propose a new strategy to generate high-energy and robust anisotropic excitons in few-layer ReS2 nanosheets by phase engineering. This approach overcomes the limitation imposed by the layer thickness, enabling production of visible polarized photoluminescence at room temperature. Ultrasonic chemical exfoliation is implemented to introduce the metallic T phase of ReS2 into the few-layer semiconducting Td nanosheets. In this configuration, light excitation can readily produce "hot" electrons to tunnel to the Td phase via the metal-semiconductor interface to enhance the overlap between the wave functions and screened Coulomb interactions. Owing to the strong electron-hole interaction, significant increase in the optical band gap is observed. Highly anisotropic and tightly bound excitons with visible light emission (1.5-2.25 eV) are produced and can be controlled by tailoring the T phase concentration. This novel strategy allows manipulation of polarized optical information and has great potential in optoelectronic devices.