Photoinduced doping effect of pentacene field effect transistor in oxygen atmosphere studied by displacement current measurement
Photoinduced doping effect of pentacene field effect transistor in oxygen atmosphere studied by displacement current measurement
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DOI：
10.1063/1.1949281
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发表时间：
2005-06-20
影响因子：
4
通讯作者：
Niwano, M
中科院分区：
文献类型：
--
作者：
Ogawa, S;Naijo, T;Niwano, M
人们普遍认为，大气中的氧可以作为电子接受掺杂剂，主要用于p型有机半导体。我们用位移电流测量法研究了氧对并五苯场效应晶体管（FET）的影响。在真空条件下，由于从源极和漏极到并五苯层的空穴注入而引起的位移电流的变化被清楚地观察到，这表明并五苯FET中的移动的载流子的起源是载流子注入。当FET在黑暗条件下暴露于氧气时，观察到空穴注入的阈值栅极电压的非常小的变化。相比之下，在暴露于氧气和光的情况下，我们观察到阈值电压降低并跨越零偏置，甚至转移到对抗空穴注入的极性。这种光致掺杂效应引起FET的漏极电流的明显增加，并且即使在辐射关闭后也保持至少几个小时。这一发现表明，有机半导体器件的性能不仅受到大气中的氧气的影响，而且还受到环境光的影响，即使在器件的加工和储存过程中也是如此。(c)2005年美国物理学会。
It is widely accepted that atmospheric oxygen can work as an electron-accepting dopant mainly to p-type organic semiconductors. We have examined the effect of oxygen on a pentacene field effect transistor (FET) with and without exposure to light using the displacement current measurement. Under vacuum conditions, the change in the displacement current due to hole injection from the source and drain electrodes to the pentacene layer is clearly observed, suggesting that the origin of the mobile carriers in the pentacene FET is carrier injection. When the FET is exposed to oxygen under dark conditions, a very small change in the threshold gate voltage for hole injection is observed. In contrast, with exposure to both oxygen and light, we observed that the threshold voltage is lowered and shifted across the zero bias and even to the polarity against hole injection. This photoinduced doping effect induces a distinct increase in the drain current of the FET, and it is maintained for at least several hours even after the irradiation is turned off. This finding suggests that the performance of organic semiconductor devices is affected not only by atmospheric oxygen but also by ambient light even during the processing and storage of the devices. (c) 2005 American Institute of Physics.