为了探究有机发光二极管(OLEDs)中三重态激子参与的多种机制共同作用下磁场效应的变化规律,揭示复杂环境下OLEDs的性能变化规律,本文在具有较高三重态激子能量的磷光材料m CP中掺入单重态与三重态激子能量共振(ES≈2ET)的荧光染料Rubre...为了探究有机发光二极管(OLEDs)中三重态激子参与的多种机制共同作用下磁场效应的变化规律,揭示复杂环境下OLEDs的性能变化规律,本文在具有较高三重态激子能量的磷光材料m CP中掺入单重态与三重态激子能量共振(ES≈2ET)的荧光染料Rubrene,制备了Rubrene掺杂型的OLEDs.实验发现,掺杂器件的电致发光磁场效应(MEL)表现出了复杂变化,且MEL的低场(B≤5 m T)和高场(5 m T≤B≤500 m T)部分随着掺杂浓度的改变都发生了明显的变化.这些MEL曲线可归结为掺杂体系内超精细相互作用、单重态激子裂变和三重态-三重态激子淬灭三种微观过程共同作用的结果;而不直接产生荧光的三重态激子,可以通过一些自旋混合过程,改变单重态激子的比例,从而对器件发光产生重要影响.器件的工作温度和注入电流密度对磁场效应的影响进一步证实了本研究组的观点.展开更多
Flexible magnetoelectric （ME） materials have been studied for new applications such as memory, energy harvesters, and magnetic field sensors. Herein, with the widely studied and progressive advantages of ME phenomen...Flexible magnetoelectric （ME） materials have been studied for new applications such as memory, energy harvesters, and magnetic field sensors. Herein, with the widely studied and progressive advantages of ME phenomena in the multiferroic field, we demonstrate a new approach for utilizing flexible ME materials as gate dielectric layers in ME organic field-effect transistors （ME-OFET） that can be used for sensing a magnetic field and extracting the ME properties of the gate dielectric itself. The magnetoelectric nanohybrid gate dielectric layer comprises sandwiched stacks of magnetostrictive CoFe2O4 nanoparticles and a highly piezoelectric poly（vinylidene fluoride-co-trifluoroethylene） layer. While varying the magnetic field applied to the ME gate dielectric, the ME effect in the functional gate dielectric modulates the channel conductance of the ME-OFET owing to a change in the effective gate field. The clear separation of the ME responses in the gate dielectric layer of ME-OFET from those of the other parameters was demonstrated using the AC gate biasing method and enabled the extraction of the ME coefficient of ME materials. Additionally, the device shows high stability after cyclic bending of 10,000 cycles at a banding radius of 1.2 cm. The device has significant potential for not only the extraction of the intrinsic characterization of ME materials but also the sensing of a magnetic field in integrated flexible electronic systems.展开更多
文摘为了探究有机发光二极管(OLEDs)中三重态激子参与的多种机制共同作用下磁场效应的变化规律,揭示复杂环境下OLEDs的性能变化规律,本文在具有较高三重态激子能量的磷光材料m CP中掺入单重态与三重态激子能量共振(ES≈2ET)的荧光染料Rubrene,制备了Rubrene掺杂型的OLEDs.实验发现,掺杂器件的电致发光磁场效应(MEL)表现出了复杂变化,且MEL的低场(B≤5 m T)和高场(5 m T≤B≤500 m T)部分随着掺杂浓度的改变都发生了明显的变化.这些MEL曲线可归结为掺杂体系内超精细相互作用、单重态激子裂变和三重态-三重态激子淬灭三种微观过程共同作用的结果;而不直接产生荧光的三重态激子,可以通过一些自旋混合过程,改变单重态激子的比例,从而对器件发光产生重要影响.器件的工作温度和注入电流密度对磁场效应的影响进一步证实了本研究组的观点.
文摘Flexible magnetoelectric （ME） materials have been studied for new applications such as memory, energy harvesters, and magnetic field sensors. Herein, with the widely studied and progressive advantages of ME phenomena in the multiferroic field, we demonstrate a new approach for utilizing flexible ME materials as gate dielectric layers in ME organic field-effect transistors （ME-OFET） that can be used for sensing a magnetic field and extracting the ME properties of the gate dielectric itself. The magnetoelectric nanohybrid gate dielectric layer comprises sandwiched stacks of magnetostrictive CoFe2O4 nanoparticles and a highly piezoelectric poly（vinylidene fluoride-co-trifluoroethylene） layer. While varying the magnetic field applied to the ME gate dielectric, the ME effect in the functional gate dielectric modulates the channel conductance of the ME-OFET owing to a change in the effective gate field. The clear separation of the ME responses in the gate dielectric layer of ME-OFET from those of the other parameters was demonstrated using the AC gate biasing method and enabled the extraction of the ME coefficient of ME materials. Additionally, the device shows high stability after cyclic bending of 10,000 cycles at a banding radius of 1.2 cm. The device has significant potential for not only the extraction of the intrinsic characterization of ME materials but also the sensing of a magnetic field in integrated flexible electronic systems.
