Storage of an electric field for photocurrent generation in ferroelectric-functionalized organic devices
Storage of an electric field for photocurrent generation in ferroelectric-functionalized organic devices
复制标题
铁电功能化有机器件中用于光电流产生的电场的存储
DOI：
10.1038/ncomms4279
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发表时间：
2014-02-01
影响因子：
16.6
通讯作者：
Awaga, Kunio
中科院分区：
文献类型：
--
作者：
Hu, Laigui;Dalgleish, Simon;Awaga, Kunio
有机光电子器件通常由电极电位差或偏置电压产生的电场驱动。虽然极化的铁电畴可能会产生定向杂散场，但在有机器件中利用它们来产生光电流的努力还很少。在这里，我们证明了在铁电极化过程中由不完全屏蔽引起的大的净场，并且可以被短的电压脉冲‘恢复’，可以促进有机半导体中激子的解离。我们发现，与电极电位差(1~10 mV m−1)相当的定向场是造成器件中光电流的原因。展示了一种由这种杂散场驱动的有机光电探测器的原型。在没有任何优化的情况下，光响应率可以达到~0.1 mA W−1。本研究为有机光电子器件中光电流的产生提供了不同的工作原理。此外，这种极性可调的光响应可能会导致新的光响应存储器件。
Organic optoelectronic devices are usually driven by the electric field generated from an electrode potential difference or bias voltage. Although poled ferroelectric domains may produce oriented stray fields, few efforts have been made to utilize them for photocurrent generation in organic devices. Here we show that large net fields caused by incomplete screening during ferroelectric polarization, and which can be ‘restored’ by short voltage pulses, can facilitate exciton dissociation in organic semiconductors. The oriented fields, comparable with that produced by an electrode potential difference (1~10 MV m−1), here are found to be responsible for the photocurrent in our devices. A prototype for an organic photodetector driven by such stray fields is demonstrated. The photoresponsivity, without any optimization, can achieve ~0.1 mA W−1. This study provides a different operation principle for the generation of photocurrent in organic optoelectronic devices. Furthermore, the polarity-tunable photoresponse may lead to new photoresponsive memory devices.