Nanotesla magnetoresistance in π-conjugated polymer devices
Nanotesla magnetoresistance in π-conjugated polymer devices
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DOI：
10.1103/physrevb.95.241407
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发表时间：
2017-06-22
影响因子：
3.7
通讯作者：
Lupton, John M.
中科院分区：
文献类型：
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作者：
Klemm, Philippe;Bange, Sebastian;Lupton, John M.
我们证明了在薄膜二极管的导电聚合物聚（苯乙烯磺酸盐）掺杂的聚（3，4-乙撑二氧噻吩）（PEDOT：PSS）的有机磁电阻的亚微特斯拉的灵敏度。磁阻灵敏度优于十亿分之二十（ppb）。对于其他共轭聚合物，磁电阻可以分为两个制度的磁场强度：非单调的超小磁场效应的磁场规模低于2 mT，和单调的中间磁场效应的规模超过几十mT。前者赋予PEDOT：PSS磁阻曲线特征W形功能，与常规有机发光二极管（OLED）器件中发现的那些相比具有反转的转折点。我们成功地解决了超小的磁场效应的PEDOT：PSS层纳入OLED结构，这是负责额外的磁阻功能的ppm规模。这样的装置在磁阻方面显示出前所未有的复杂性，在+/-1 mT的场范围内总共有四个极值。我们提出，这些独特的特性产生于自旋-自旋相互作用的弱束缚载流子对负责自旋相关的复合探测磁阻。
We demonstrate submicrotesla sensitivity of organic magnetoresistance in thin-film diodes made of the conducting polymer poly(styrene sulfonate)-doped poly(3,4-ethylenedioxythiophene) (PEDOT:PSS). The magnetoresistance sensitivity is shown to be better than 20 parts per billion (ppb). As for other conjugated polymers, magnetoresistance can be separated into two regimes of field strength: the nonmonotonic ultrasmall magnetic field effect on magnetic field scales below 2 mT, and the monotonic intermediate magnetic field effect on scales over several tens of mT. The former gives the PEDOT:PSS magnetoresistance curve a characteristic W-shaped functionality, with inverted turning points compared to those found in conventional organic light-emitting diode (OLED) devices. We succeed in resolving the ultrasmall magnetic field effect of the PEDOT: PSS layer incorporated within an OLED structure, which is responsible for an additional magnetoresistive feature on the ppm scale. Such a device shows unprecedented complexity in magnetoresistance with a total of four extrema within a field range of +/- 1 mT. We propose that these unique characteristics arise from spin-spin interactions in the weakly bound carrier pairs responsible for the spin-dependent recombination probed in magnetoresistance.