High circular polarization in electroluminescence from MoSe2
High circular polarization in electroluminescence from MoSe2
复制标题
DOI：
10.1063/1.4942367
复制
发表时间：
2016-02
影响因子：
4
通讯作者：
M. Onga;Yijin Zhang;R. Suzuki;Y. Iwasa
中科院分区：
文献类型：
--
作者：
M. Onga;Yijin Zhang;R. Suzuki;Y. Iwasa
谷自由度与光学螺旋度之间的耦合是过渡金属二硫族化合物中的独特现象之一。从圆偏振光致发光（PL）评估的显着的谷偏振已被报道在许多过渡金属二硫属化物，除了在MoSe 2。该化合物是一种反常材料，显示出谷极化态的超快弛豫，这导致PL中的极化可以忽略不计。另一方面，最近在WSe 2发光晶体管中报道了圆偏振电致发光（EL），提供了使用谷自由度的另一种方法。在这里，我们报告的电致发光性能的MoSe 2，演示电开关的光学螺旋。重要的是，我们观察到高圆偏振达到66%。结果表明，与PL形成鲜明对比的是，圆偏振EL的主导机制对谷间散射是鲁棒的。
The coupling between the valley degree of freedom and the optical helicity is one of the unique phenomena in transition metal dichalcogenides. The significant valley polarization evaluated from circularly polarized photoluminescence (PL) has been reported in many transition metal dichalcogenides, except in MoSe2. This compound is an anomalous material showing ultra-fast relaxation of the valley polarized states, which causes negligible polarization in the PL. Meanwhile, circularly polarized electroluminescence (EL) has been recently reported in a WSe2 light-emitting transistor, providing another method for using the valley degree of freedom. Here, we report the EL properties of MoSe2, demonstrating electrical switching of the optical helicity. Importantly, we observed high circular polarization reaching 66%. The results imply that the dominant mechanism of circularly polarized EL is robust against intervalley scattering, in marked contrast to the PL.