Optical Investigations of Nano‐LEDs Based on Submicron‐Sized III‐Nitride Platelets

A study of submicron‐sized InGaN containing a single quantum well, intended for use as nano‐light‐emitting diodes in high‐resolution display based on direct emission, is presented. Herein, the structures are grown by a bottom‐up method from holes in a masked GaN/sapphire substrate and are intended for red emission. Many of the platelets show dark lines in cathodoluminescence images, previously identified as stacking mismatch boundaries. These introduce local shifts in the reduced emission, perhaps related to local strain. However, the total emission position stays unaffected, just reduced in intensity. Due to an unintended variation in the size of the c‐facet, there is a gradient in the indium content which, in turn, leads to a significant shift in the peak position of the quantum well emission. With increasing probe current there is a slight blueshift, likely a result of the quantum confined Stark effect.