Effect of traps on the charge transport in semiconducting polymer PCDTBT
Effect of traps on the charge transport in semiconducting polymer PCDTBT
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DOI：
10.1016/j.sse.2018.04.005
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发表时间：
2018-07-01
影响因子：
1.7
通讯作者：
Gupt, Vinay
中科院分区：
文献类型：
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作者：
Khan, Mohd Taukeer;Agrawal, Vikash;Gupt, Vinay
有机半导体(OSC)如今被称为下一代电子器件的有前途的候选者。由于这些材料的无序结构，在其能带隙中存在高密度的陷阱，这影响了这些器件的性能。在本文中，我们通过测量只有空穴的器件结构中随温度变化的J(V)特性，研究了陷阱在PCDTBT薄膜电荷输运中的作用。用空间电荷限制(SCL)导电模型对实验结果进行了分析。发现无陷阱SCL电导的室温J(V)特性服从Mott-Gurney平方定律。但在278K以下，电流按陷阱填充SCL定律增加，陷阱呈指数分布在半导体禁带内。此外，在达到类似于12V的V-c交叉电压后，由注入载流子填充的所有陷阱和填充陷阱的SCL电流都切换到无陷阱的SCL电流。无陷阱SCL电流的空穴迁移率比填充陷阱的SCL电流高一个数量级，且随温度变化不变。
Organic semiconductors (OSCs) are nowadays called upon as promising candidates for next generation electronics devices. Due to disorder structure of these materials, a high density of traps are present in their energy band gap which affect the performance of these devices. In the present manuscript, we have investigated the role of traps on charge transport in PCDTBT thin film by measuring the temperature dependent J(V) characteristics in hole only device configuration. The obtained results were analyzed by space charge limited (SCL) conduction model. It has been found that the room temperature J(V) characteristics follow Mott-Gurney square law for trap-free SCL conduction. But below 278 K, the current increases according to trap-filling SCL law with traps distributed exponentially in the band gap of semiconductor. Furthermore, after reaching a crossover voltage of V-c similar to 12 V, all the traps filled by injected carriers and the trap-filling SCL current switch to trap-free SCL current. The hole mobility of trap-free SCL current is about one order higher as compared trap-filling SCL current and remains constant with temperature.