By utilizing the PFOPV material with the characteristic of exciton
states and Charge-Transfer States (CTS) coexisting, polymer light-emitting
device with structure of ITO/PEDOT:PSS/PFOPV/CsF/Al was fabricated,
and the magnetic field effects on current (magnetoconductance, MC)
were measured at different temperatures and bias voltages. We found
that positive-negative inversion of MC could be tuned via modifying
the ratio of exciton states to CTS, i.e., when the relative proportion
of CTS was quite high in the device, the MC at both high fields (>40
mT) and low fields (
中央高校基本科研业务费专项资金资助项目(XDJK2014C081)
重庆市科委自然科学基金(CSTC2010BA6002)
国家自然科学基金(11374242)
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图1
(网络版彩图)(a) PFOPV分子的化学结构; (b) PFOPV中各激发态的形成和自旋相关的转变过程; (c) 不同微观过程所对应的MC曲线线型
图2
(网络版彩图)(a) 器件在不同温度下的发光-电流-电压特性曲线; (b) 器件在300 K下的MC曲线随注入电流的变化; (c) 200 K下的MC实验曲线及其拟合曲线(红色实线), 为了清晰, 曲线已进行适当上下平移; (d) 200 K, 20
图3
(网络版彩图)(a) 器件在150 K时的MC实验曲线及其拟合结果; (b) 相关拟合参数随注入电流的变化; (c) 由3种不同过程共同作用而形成的一种MC(模拟)曲线线型; (d) 150 K时, EL谱随偏压(注入电流)的变化
图4
(网络版彩图)(a) 相关拟合参数随温度的变化情况; (b) 器件在不同温度下的EL谱, 所有曲线对第1峰归一化处理
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