Subwavelength molecular opto-electronic devices based on plasmonic nano antennas

我们提出了一种新的有机发光二极管(OLED)的方法，该方法基于将超薄的层状功能分子结构集成到亚波长共振等离子体纳米天线中。金属纳米天线不仅增强了光发射，同时也为载流子注入提供了稳定的电触点。这一概念的力量源于这样一个事实，即这种有机/金属混合光电子器件的关键功能，包括向分子结构中注入电荷-载流子，辐射电荷-载流子复合，以及最后，等离子体的激发和光子的发射，紧密地集成到一个单一的亚波长纳米光电系统中。纳米天线的设计决定了辐射方向图、发射极化、激子寿命和光谱，从而从根本上控制了光子发射过程及其动力学。通过电寻址不同的天线区域，可以将进一步的功能集成到这样的纳米像素中。图1总结了这一方案的设想，显示了在超薄的有机传输和复合层上的单晶天线结构和单晶金的底部接触。我们的方法可能会为OLED的尺寸、效率、寿命和辐射特性以及新的电泵浦等离子体混合器件开辟新的前景。这种电驱动亚波长光子源的可能应用在于例如显示技术领域，该技术利用非常小的像素尺寸来提供改进的图像质量，并且在未来适应例如无护目镜的3D技术或实现半透明显示。我们的方法还将为工作在电信光谱区域的非传统非经典光源开辟新的前景，并且通过适当地管理损耗，例如通过使用暗共振，有可能进入强耦合区域来研究电抽运激子-偏振子物理和低阈值激光。为了实现拟议的概念，我们协同结合了两个实验小组的专业知识。赫克特集团专门从事单晶纳米天线和等离子激元的研究。Pflum集团在有机半导体及其在薄膜光电子器件中的应用方面经验丰富。

We propose a new approach to organic light emitting diodes (OLEDs) based on the integration of an ultrathin layered functional molecular architecture into subwavelength resonant plasmonic nanoantennas. The metallic nanoantenna not only enhances light emission but at the same time serves as a stable electrical contact for charge carrier injection. The power of the concept arises from the fact that the key functions of such a hybrid organic/metallic opto-electronic device, comprising charge-carrier injection into a molecular architecture, radiative charge-carrier recombination, as well as finally, the excitation of plasmons and emission of photons, become tightly integrated into a single subwavelength nano-electro-optical system. The nanoantenna design determines the radiation pattern, emission polarization, exciton lifetime and spectrum resulting in a fundamental control over the photon emission process and its dynamics. Further functionality can be integrated into such a nano-pixel by electrically addressing different antenna regions. Fig. 1 summarizes the vision of this proposal showing a single-crystalline antenna structure on top of ultrathin organic transport and recombination layers and a single-crystalline gold bottom contact. Our approach may open new perspectives for OLED size, efficiency, lifetime and radiation characteristics as well as for new electrically pumped plasmonic hybrid devices in general. Possible applications of such electrically-driven subwavelength photon sources lie e.g. in the field of display technology utilizing very small pixel dimensions to provide improved image quality and, in future, to accommodate e.g. goggle-free 3D technologies or to realize semitransparent displays. Our approach will also open new perspectives for unconventional nonclassical light sources operating in the telecom spectral region, and, by proper management of losses, e.g. by using dark resonances, it may be possible to enter the strong-coupling regime to study electrically-pumped exciton-polariton physics and low-threshold lasing. To realize the proposed concept we synergistically combine the expertise of two experimental groups. The Hecht group is specialized in single-crystalline nano-antennas and plasmonics. The Pflaum group is experienced in organic semiconductors and their implementation in thin-film opto-electronic devices.