Ambipolar Charge Transport in Organic Semiconductors and Devices

近年来，有机电子学领域取得了巨大的进步，主要是因为它们在电子设备中的新兴应用。晶体管是当今微电子电路核心的一个非常重要的电子设备，因为它代表着所有日常电子产品的组成部分。最近，有机晶体管也在一些电子器件中首次亮相，可以被认为是硅基器件在一系列低成本和大容量应用中的可能替代品。尽管最近的进展令人印象深刻，但由于目前无法满足最低要求(速度、功耗、成本)，有机晶体管在实际应用中的使用受到阻碍。拟议的工作使用一种完全不同的方法来解决这些具体问题。我们将研究既能传输电子又能传输空穴的有机半导体的电子性质。这些就是所谓的双极有机半导体。在此期间，我们将发展和推进关于有机半导体中双极输运的知识，但我们也将开发和评估各种相关的技术现象。我们将首先通过电学、结构、化学和光谱测量相结合的方法来研究一些已知的双极有机半导体中的双极输运。了解这些材料的关键电子性质对于开发改进的或新的半导体至关重要，这些半导体将随后通过与各种化学小组的合作来合成。利用所获得的知识，我们将演示双极有机晶体管，并首先演示基本的逻辑电路，如电压反相器。预计这项工作将带来发光晶体管和传感器等新的应用。此外，了解有机材料中的双极输运具有基本的科学兴趣，预计将有利于包括化学和材料科学在内的其他科学学科。

Recent years have seen tremendous advances in the area of organic electronics mainly motivated by their emerging applications in electronic devices. A very important electronic device that is in the heart of today's microelectronic circuits is the transistor since it represents the building block of all everyday electronics. Very recently, organic based transistors also made their debut in a number of electronic devices and can be arguably viewed as possible alternatives to silicon-based devices in a range of low-cost and high-volume applications.Although recent progress is impressive, use of organic transistors in practical applications is hampered because the minimum requirements (speed, power-dissipation, cost) presently cannot be meet. The proposed work addresses these specific problems using an entirely different approach. We will study the electronic properties of organic semiconductors that are capable of transporting both electrons and holes. These are the so-called ambipolar organic semiconductors. During this fellowship we will develop and advance the knowledge on ambipolar transport in organic semiconductors but we will also exploit and assess various technologically relevant phenomena.We will first study ambipolar transport in a number of known ambipolar organic semiconductors through a combination of electrical, structural, chemical and spectroscopic measurements. Understanding the key electronic properties of these materials is essential for the development of improved or new semiconductors that will be subsequently synthesized through collaborations with various chemistry groups. Using the obtained knowledge, we will demonstrate ambipolar organic transistors and, initially, basic logic circuits like voltage inverters. New applications such as light-emitting transistors and sensors are expected to arise as a result of this work. Moreover, understanding ambipolar transport in organic materials is of basic scientific interest and is expected to benefit other scientific disciplines including chemistry and material science.