Diffusionlike electric-field migration in the channel of organic field-effect transistors
Diffusionlike electric-field migration in the channel of organic field-effect transistors
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DOI：
10.1103/physrevb.78.121302
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发表时间：
2008-09-01
影响因子：
3.7
通讯作者：
Iwamoto, Mitsumasa
中科院分区：
文献类型：
--
作者：
Manaka, Takaaki;Liu, Fei;Iwamoto, Mitsumasa
时间分辨显微光学二次谐波产生（TRM-SHG）技术为研究有机场效应晶体管（OFET）中载流子的动力学行为提供了一种新的途径。与许多常用的方法不同，TRM二次谐波法直接探测OFET沟道中的瞬态电场分布，具有很高的时间和空间分辨率。在这项工作中，我们使用这种技术来定量研究电场峰值的迁移。我们发现，在很宽的实验条件下，电场峰值的迁移遵循扩散行为;即，（x）的峰值位置的平方在bar上与时间t成正比。基于二维计算模拟和一般的载流子输运机制，我们提出这种行为源于一个简单的关系，μ类似于或等于γ（x）除以bar（2）/（t垂直bar V-gs垂直bar），其中μ是载流子迁移率，γ是约0.5的常数，V-gs是相对于源极电压的栅极电压。实验和模拟数据很好地支持了这种关系。
Time-resolved microscopic optical second-harmonic generation (TRM-SHG) technique provides a different approach to study the dynamics of carriers in organic field-effect transistor (OFET). Different from many common methods, the TRM SHG directly probes the transient electric-field distribution in the channel of the OFET in high temporal and spatial resolutions. In this work we used this technique to quantitatively study migration of the peak of the electric field. We found that under a broad range of experimental conditions, the migration of the peak of the electric field follows a diffusionlike behavior; namely, the square of the peak position of (x) over bar is proportional to time t. Based on a two-dimensional computational simulation and general carrier transport mechanism, we proposed that this behavior arises from a simple relation, mu similar or equal to gamma(x) over bar (2)/(t vertical bar V-gs vertical bar), where mu is the carrier mobility, gamma is constant about 0.5, and V-gs is the gate voltage with respect to the source voltage. The experimental and simulation data well supported this relationship.