Fabrication of Vertically Aligned InGaN/GaN Nanorod Light Emitting Diode Arrays Using Dielectrophoresis.

We report a novel strategy for vertical alignment of nanorod light emitting diodes (NRLs) by introducing dielectrophoresis (DEP) coupled with a nanohole electrode (NHE). The NHE consists of two electrodes placed at the top and the bottom separated by an insulating layer. This electrode structure allows NRLs to align within the nanoholes due to the nonuniform electric field generated across the entire region of the nanohole when a DEP voltage is applied. Our strategy involves optimizing the nanohole dimensions (diameter and height) to ensure the vertical positioning and alignment of NRLs within the nanohole, rather than laying them down horizontally. The NHE arrays with relatively large dimensions of 30 × 30 and 50 × 50 μm exhibit alignment yields of 76% and 58%, respectively. Additionally, the smaller NHE dimension of 10 × 10 μm achieves a 100% alignment yield, thereby enabling the fabrication of ultrasmall pixels. This approach represents a highly feasible direction for the precise placement of individual NRLs at a specific location, leading to the development of ultrasmall, high-resolution display pixels.