Light scattering studies of organic field-effect transistors

本研究的目的是利用光散射技术研究界面控制的有机场效应晶体管（OFFETs）的电荷输运特性，并将OFFETs应用于存储器件。该方法包括：（1）利用脉冲激光沉积逐层生长聚合物薄膜，以控制OFFET中的半导体-介质界面;（2）利用来自偏压OFET结构的拉曼光谱探测介质-半导体界面，并将振动光谱的变化与理论相关联，以确定电荷输运时的结构变化;（3）OFFET的电荷调制光谱;（4）金属纳米颗粒掺杂的电介质和有机半导体的表面增强拉曼散射及其存储应用：本研究将光散射技术与传统的电流-电压特性相结合，全面探测OFFEs中的电荷输运，获得界面处电子-声子相互作用和结构变化的信息。这种技术具有潜在的变革性，因为它有望成为研究其他光电器件中电荷传输机制的标准探针。这一假设将在有机存储器应用中得到进一步验证，在有机存储器应用中，将进行表面增强拉曼散射研究，以深入了解存储器设备的操作。这项工作的更广泛影响体现在从林肯大学（一所历史上的黑人学院大学）招募本科生实习生，包括代表性不足的少数民族，为他们提供尖端研究的机会。拟议的工作包括参与和培训研究生，这将有助于美国在有机光电子领域的劳动力。

The objective of this research is to investigate charge transport properties in interface-controlled organic field-effect transistors (OFETs) using light scattering techniques, with a long term goal of applying OFETs in memory devices. The approach includes (1) layer-by-layer growth of polymer films using pulsed laser deposition to control the semiconductor-dielectric interface in OFETs; (2) probing the dielectric-semiconductor interface using Raman spectroscopy from biased OFET structures and correlating the changes in the vibrational spectra with theory to identify the structural changes upon charge transport; (3) charge modulation spectroscopy of OFETs; (4) surface-enhanced Raman scattering from metal nanoparticle doped dielectric and organic semiconductors for memory applications.The proposed research takes a comprehensive approach to probe charge transport in OFETs by combining light scattering techniques with conventional current-voltage characteristics, yielding information on electron-phonon interactions and structural changes at the interface. Such a technique has a potential transformative character as it promises to become a standard probe for studying charge transport mechanisms in a host of other optoelectronic devices. This hypothesis will be further put to test in organic memory applications where surface-enhanced Raman scattering studies will be carried out to gain insight into the operation of memory devices.The broader impact of the work is demonstrated by recruitment of undergraduate interns including underrepresented minorities from Lincoln University (a Historically Black College & University) to give them opportunities in cutting-edge research. The proposed work involves participation and training of graduate students which will contribute to the US workforce in the area of organic optoelectronics.