Spectrally resolved hyperfine interactions between polaron and nuclear spins in organic light emitting diodes: Magneto-electroluminescence studies
Spectrally resolved hyperfine interactions between polaron and nuclear spins in organic light emitting diodes: Magneto-electroluminescence studies
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DOI：
10.1063/1.4898700
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发表时间：
2014-09
影响因子：
4
通讯作者：
S. Crooker;Feilong Liu;Megan R. Kelley;N. J. D. Martinez;W. Nie;A. Mohite;Iffat H Nayyar;S. Tretiak
中科院分区：
文献类型：
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作者：
S. Crooker;Feilong Liu;Megan R. Kelley;N. J. D. Martinez;W. Nie;A. Mohite;Iffat H Nayyar;S. Tretiak
我们利用光谱分辨的磁致发光（EL）测量方法研究了有机发光二极管中极化子与核自旋之间的超精细相互作用的能量依赖性。使用产生明亮激基复合物发射的分层器件，我们表明，由于100 mT量级的小外加磁场，EL发射强度I的增加在EL光谱的高能蓝端（ΔI/I = 11%）明显大于低能红端（ΔI/I = 4%）。同时，磁致发光曲线的宽度单调增加，从蓝色到红色，揭示了极化子和核之间的超精细耦合的增加，并直接提供洞察的能量依赖的空间范围和极化子的本地化。
We use spectrally resolved magneto-electroluminescence (EL) measurements to study the energy dependence of hyperfine interactions between polaron and nuclear spins in organic light-emitting diodes. Using layered devices that generate bright exciplex emission, we show that the increase in EL emission intensity I due to small applied magnetic fields of order 100 mT is markedly larger at the high-energy blue end of the EL spectrum (ΔI/I ∼ 11%) than at the low-energy red end (∼4%). Concurrently, the widths of the magneto-EL curves increase monotonically from blue to red, revealing an increasing hyperfine coupling between polarons and nuclei and directly providing insight into the energy-dependent spatial extent and localization of polarons.