The concept of solid-state light-emitting electrochemical cells (LECs), proposed in 1995, opened a new field in display and lighting technologies. The key advantage of this technology derives from a single emissive layer containing an emissive material and an ionic salt. Mobile ions in the emissive layer induce electrochemical doping at electrodes and thus the operation voltage can be reduced even if using air-stable electrodes. Since the first demonstration of LECs, many materials-oriented efforts have been made in improving device performance of LECs. However, some difficulties arising from material properties limit further optimizing the device characteristics of LECs. Recently, optical techniques have been shown to achieve better device properties without using new materials. Light extraction techniques recycle the light trapped in layered device structure and thus enhance the light output and efficiency of LECs. Recombination zone probing techniques offer direct evidence of carrier balance in LECs and is helpful in optimizing device performance. Spectral filtering based on microcavity effects and localized surface plasmon resonance from metal nanoparticles have the advantages of easy fabrication and compatibility with device processing of LECs. This Minireview provides an overview of the three categories of recent advances in optical techniques for LECs.

中文翻译：

---

发光电化学电池的光学技术。

1995年提出的固态发光电化学电池（LEC）概念为显示和照明技术开辟了一个新领域。该技术的主要优势来自包含发光材料和离子盐的单个发光层。发射层中的移动离子在电极上引起电化学掺杂，因此即使使用空气稳定的电极也可以降低工作电压。自从首次展示LEC以来，在改善LEC的器件性能方面已进行了许多面向材料的工作。然而，由于材料特性而引起的一些困难限制了进一步优化LEC的器件特性。最近，光学技术已显示出无需使用新材料即可获得更好的器件性能。光提取技术可回收捕获在分层设备结构中的光，从而提高LEC的光输出和效率。重组区探测技术提供了LEC中载流子平衡的直接证据，并有助于优化设备性能。基于微腔效应和金属纳米粒子局部表面等离振子共振的光谱过滤具有易于制造且与LEC的器件加工兼容的优点。本小型审查概述了LEC光学技术的最新进展的三类。基于微腔效应和金属纳米粒子局部表面等离振子共振的光谱过滤具有易于制造且与LEC的器件加工兼容的优点。本小型审查概述了LEC光学技术的最新进展的三类。基于微腔效应和金属纳米粒子局部表面等离振子共振的光谱过滤具有易于制造且与LEC的器件加工兼容的优点。本小型审查概述了LEC光学技术的最新进展的三类。