Light Emission From Ambipolar Semiconducting Polymer Field Effect Transistors

技术概要：双极性聚合物发光场效应晶体管（LEFET）已经得到证实。直接成像显示在通道内的狭窄区域中发射。发射区的位置和光强由栅极偏压控制。 发射区在电子和空穴电流相等的交叉点处靠近通道的中心。 在发射区中的栅极偏置引起的移位和双极电荷传输表明该器件是真正的发光晶体管。资助的研究将集中在实现发光场效应晶体管的操作的基本理解，以优化发射亮度和效率的目标。具体任务包括：a.通过增加栅极电介质的电容（Ci）和通过减小LEFET的沟道长度来降低聚合物LEFET的工作电压。B.在空间和光谱上解析光发射。C.测试LEFET中作为有源层的不同半导体聚合物以及源极和漏极的不同金属。D.将亮度推到可能的最高水平：e.脉冲LEFET操作根据电介质强度和厚度，在足够高的直流偏置下，所有的LEFET都会击穿。 为了进一步增强亮度，将通过脉冲电压操作探索更高的驱动电压。非技术性总结：发光场效应晶体管的研究处于半导体和金属聚合物的跨学科领域以及塑料电子学的新兴领域的最前沿。半导体聚合物发光场效应晶体管--塑料发光场效应晶体管的演示是塑料电子领域的重大突破。这一进展为研究这种新型设备概念的基础科学和应用科学提供了机会。发光场效应晶体管的制备和研究涉及到聚合物科学、凝聚态物理、器件科学、材料化学、界面化学和材料科学等多个学科的综合。因此，委员会认为，该领域的研究非常适合于研究生和博士后研究人员的跨学科教育和培训。所提出的研究的目标是实现足够高的亮度，以实现潜在的重要应用，例如使用每个发光场效应晶体管作为包括这种器件阵列的平板显示器中的像素，和/或或者使用发光场效应晶体管的结构来演示来自半导体聚合物的注入激光器。

TECHNICAL SUMMARY: Ambipolar polymer light emitting field-effect transistors (LEFETs) have been demonstrated. Direct imaging showed emission in a narrow region within the channel. The light intensity and the location of the emission zone are controlled by the gate bias. The emission zone is near the center of the channel at the crossover point where the electron and hole currents are equal. The gate bias induced shift in the emission zone and the ambipolar charge transport indicate that the device is truly a light emitting transistor. The funded research will focus on achieving a fundamental understanding of the operation of the light emitting field effect transistor with the goal of optimizing the emission brightness and efficiency. Specific tasks include the following:a. Lower the operating voltage for the polymer LEFET by increasing the capacitance of the gate dielectric (Ci) and by reducing the channel length of the LEFET. b. Spatially and spectrally resolve the light emission. c. Test different semiconducting polymers as the active layer in LEFETs and different metals for the source and drain electrodes. d. Push brightness to the highest level possible: e. Pulsed LEFET OperationAll dielectrics break down at sufficiently high DC bias, based on dielectric strength and thickness. To further enhance brightness, even higher drive voltages will be explored through pulsed voltage operation. NON-TECHNICAL SUMMARY: Research on light emitting field-effect transistors is at the forefront of the interdisciplinary field of semidonducting and metallic polymers and the emerging field of plastic electronics. The demonstration of light emitting field-effect transistors fabricated from semiconducting polymers --- plastic light emitting field-effect transistors --- is a significant breakthrough in the field of plastic electronics. This progress provides an opportunity to study both the fundamental science and the applied science of this novel device concept. The fabrication and study of light emitting field effect transistors involves a combination of polymer science, condensed matter physics, device science, materials chemistry, interface chemistry and materials science. Consequently, research in this area is ideally suited for the interdisciplinary education and training of graduate students and post-doctoral researchers.A goal of the proposed research is the achievement of sufficiently high brightness to enable potentially important applications such as using each light emitting field-effect transistor as a pixel in a flat panel display comprising an array of such devices and/or using the architecture of the light emitting field-effect transistor to demonstrate injection lasers from semiconducting polymers.