Fundamentals in Organic Light Emitting Diodes

晶体管和激光器等固态电子设备一直在不断改变我们今天生活的社会。然而，固态发光器件并没有征服爱迪生的白炽灯泡。灯泡是相当浪费的;大约98%的能量输入最终以热量而不是光的形式结束。美国能源部估计，如果广泛采用节能固态照明，将节省约190太瓦时的能源，这将减少绿色房屋3140万公吨的碳排放。该提案的重点是研究表面和界面材料，这是开发简单高效的有机发光二极管（OLED）的关键，从而有助于加速从灯泡到固态照明的过渡。具体来说，这一建议NSERC发现研究计划 将包括以下研究目标： (a)阳极接口;我们将探讨使用表面单分子层终止方法（例如氯化）的高功函数阳极的科学原理和制造方法。其目的是通过稳定电极-有机界面来提高OLED的寿命，并提高电荷平衡因子。 (b)阴极界面和电子注入缓冲层;我们将开发一种多功能的纳米复合缓冲材料，同时优化几个关键参数，包括界面处的光学常数匹配、导热和电导率。目标是提高电荷平衡因子和光耦合。 (c)有机异质结;我们将研究导致激子形成的各种过程。激子的后续扩散，辐射复合，非辐射复合，与累积电荷的相互作用将被研究。目标是揭示设计有机异质结以获得最大光子产生率的指导性科学原理。

Solid-state electronic devices such as transistors and lasers have been continuously transforming the society we live in today. Solid-state light-emitting devices, however, has not conquered Edison's incandescent light bulbs. The light bulbs are quite wasteful; some 98% of the energy input ends up as heat instead of light. US department of Energy has estimated that energy efficient solid-state lightings, if broadly adopted, would provide approximately 190 terawatt-hours in energy saving, which would reduce green house emissions by 31.4 million metric tons of carbon. This proposal is to focus on studying surface and interface materials which are key to develop simple and efficient organic light emitting diodes (OLED) and thus would help accelerate the transition from bulb to solid-state lightings. Specifically, this proposed NSERC discovery research program will include the following research objectives: (a) Anode interface; we will investigate the scientific principles and fabrication methods of high work function anodes using surface monolayer termination method such as chlorination. The goal is to improve OLED lifetime through stabilized electrode-organic interface and to improve charge balance factor. (b) Cathode interface and electron injection buffer layer; we will develop a versatile nano-composite buffer materials which will simultaneously optimize several key parameters including optical constant matching at the interface, thermal conduction, and electrical conductivity. The goal is to improve charge balance factor and optical coupling. (c) Organic heterojunctions; we will investigate the various processes leading to the formation of excitons. The exciton's subsequent diffusion, radiative recombination, non-radiative recombination , interaction with accumulated charges will be investigated. The goal is to uncover guiding scientific principles in designing organic heterojunctions for maximum photon generation rate .