Factors affecting the polarity and magnitude of photoresponse of transient photodetectors
Factors affecting the polarity and magnitude of photoresponse of transient photodetectors
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DOI：
10.1039/c6cp00093b
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发表时间：
2016-03-07
影响因子：
3.3
通讯作者：
Awaga, K.
中科院分区：
文献类型：
--
作者：
Reissig, L.;Mori, K.;Awaga, K.
在标准有机MSM太阳能电池架构中，在金属电极（M）之一与光敏半导体层（S）之间添加绝缘层（I）将DC光电流响应改变为强瞬态信号。简单地说，这种装置可以被认为是与充电电容器（I）接触的充电电压源（S）。如果器件内的各种预极化协同作用，则光电流信号的幅度可以通过有源层与绝缘层的紧密接触而强烈增强。在这项研究中，内置的设备上的光电流响应的极性和幅度的电位的效果进行了研究，使用良好的表征本体异质结共混系统的聚（3-hexylthiophenone）：[6，6]-苯基-C-61-丁酸甲酯（P3 HT：PCBM）作为半导体层，和作为绝缘层的离子液体。这项研究表明，响应的极性不是简单地由外部电极的能级差决定的，而是通过设备中所有能级的微妙相互作用决定的。此外，这些观察结果可以在具有固态绝缘体层的器件中重现，其中可以认为不存在离子液体的可能副作用，例如溶胀和掺杂。
The addition of an insulating layer (I) between one of the metal electrodes (M) and the photoactive semiconducting layer (S) in a standard organic MSM solar cell architecture changes the DC photocurrent response into a strong transient signal. Such a device can, in simple terms, be thought of as a charging voltage source (S) in contact with a charging capacitor (I). The magnitude of the photocurrent signal can be strongly enhanced through the intimate contact of the active layer with the insulating layer, if the various pre-polarizations within the device act synergically. In this study, the effect of the built-in potentials within the device on the polarity and magnitude of the photocurrent response is studied using the well-characterized bulk heterojunction blend system of poly(3-hexylthiophenone):[6,6]-phenyl-C-61-butyric acid methyl ester (P3HT:PCBM) as the semiconductor layer, and an ionic liquid as the insulating layer. This study shows that the polarity of the response is not simply determined by the energy level difference of the outer electrodes, but through a delicate interplay of all the energy levels in the device. Furthermore, these observations could be reproduced for devices with a solid-state insulator layer, where possible side-effects of the ionic liquid, such as swelling and doping, could be considered absent.