Department of Chemistry, Kookmin University , Seoul 02707, Republic of Korea.
Department of Materials Science and Engineering, Korea University , Seoul 02841, Republic of Korea.
ACS Appl Mater Interfaces. 2017 Nov 1;9(43):37912-37920. doi: 10.1021/acsami.7b09794. Epub 2017 Oct 19.
We introduce an orientation-controlled alignment process of p-GaN/InGaN multiquantum-well/n-GaN (p/MQW/n InGaN) nanorod light-emitting diodes (LEDs) by applying the direct current (DC) offset-alternating current (AC) or pulsed DC electric fields across interdigitated metal electrodes. The as-forwardly aligned p/MQW/n InGaN nanorod LEDs by a pulsed DC dielectrophoresis (DEP) assembly process improve the electroluminescence (EL) intensities by 1.8 times compared to the conventional AC DEP assembly process under DC electric field operation and exhibit an enhanced applied current and EL brightness in the current-voltage and EL intensity-voltage curves, which can be directly used as the fundamental data to construct DC-operated nanorod LED devices, such as LED areal surface lightings, scalable lightings (micrometers to inches) and formable surface lightings. The enhancement in the applied current, the improved EL intensity, and the increased number of forwardly aligned p/MQW/n InGaN nanorods in panchromatic cathodoluminescence images confirm the considerable enhancement of forwardly aligned one-dimensional nanorod LEDs between two opposite electrodes using DC offset-AC or a pulsed DC electric field DEP assembly process. These DC offset-AC or pulsed DC electric field DEP assembly processes suggest that designing for these types of interactions could yield new ways to control the orientation of asymmetric p/MQW/n InGaN diode-type LED nanorods with a relatively low aspect ratio.
我们介绍了一种通过在叉指金属电极上施加直流（DC）偏移交流（AC）或脉冲直流电场来控制 p-GaN/InGaN 多量子阱/n-GaN（p/MQW/n InGaN）纳米棒发光二极管（LED）取向的对准工艺。通过脉冲直流介电泳（DEP）组装工艺正向对准的 p/MQW/n InGaN 纳米棒 LED，与在直流电场下操作的传统 AC DEP 组装工艺相比，电致发光（EL）强度提高了 1.8 倍，并在电流-电压和 EL 强度-电压曲线中表现出增强的应用电流和 EL 亮度，这些可以直接用作构建直流操作纳米棒 LED 器件的基本数据，例如 LED 平面照明、可扩展照明（从微米到英寸）和可成形表面照明。正向对准的 panchromatic 阴极发光图像中应用电流的增强、EL 强度的提高以及更多正向对准的 p/MQW/n InGaN 纳米棒数量，证实了在两个相对电极之间使用直流偏移 AC 或脉冲直流电场 DEP 组装工艺，对一维纳米棒 LED 的正向对准有了相当大的增强。这些直流偏移 AC 或脉冲直流电场 DEP 组装工艺表明，对这些类型的相互作用进行设计可能会为控制具有相对低纵横比的不对称 p/MQW/n InGaN 二极管型 LED 纳米棒的取向提供新的方法。
