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（ofet）的电荷传输特性，并将其应用于存储器件。该方法包括：(1)利用脉冲激光沉积技术逐层生长聚合物薄膜，以控制ofet中的半导体-介电界面；(2)利用偏置OFET结构的拉曼光谱探测介电-半导体界面，并将振动光谱的变化与理论联系起来，以识别电荷输运时的结构变化；(3) ofet的电荷调制光谱；(4)金属纳米颗粒掺杂电介质和有机半导体的表面增强拉曼散射。本研究将光散射技术与传统的电流-电压特性相结合，采用综合的方法来探测ofet中的电荷输运，从而获得电子-声子相互作用和界面结构变化的信息。这种技术具有潜在的变革性，因为它有望成为研究许多其他光电器件中电荷输运机制的标准探针。这一假设将进一步在有机存储器应用中进行测试，其中将进行表面增强拉曼散射研究，以深入了解存储器器件的操作。这项工作的广泛影响体现在招收本科生实习生，包括来自林肯大学（一所历史悠久的黑人大学）的代表性不足的少数族裔，为他们提供从事前沿研究的机会。拟议的工作涉及研究生的参与和培训，这将有助于美国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.