Directly addressable GaN-based nano-LED arrays: fabrication and electro-optical characterization

The rapid development of display technologies has raised interest in arrays of self-emitting, individually controlled light sources atthe microscale. Gallium nitride (GaN) micro-light-emitting diode (LED) technology meets this demand. However, the current technology is not suitable for the fabrication of arrays of submicron light sources that can be controlled individually. Our approach is based on nanoLED arrays that can directly address each array element and a self-pitch with dimensions below the wavelength of light. The design and fabrication processes are explained in detail and possess two geometries: a 6 x 6 array with 400nm LEDs and a 2 x 32 line array with 200nm LEDs. These nanoLEDs are developed as core elements of a novel on-chip super-resolution microscope. GaN technology, based on its physical properties, is an ideal platform for such nanoLEDs. Tiny lights enable molecular-scale imagingArrays of nanoscale light-emitting diodes (LEDs) offer an energy-efficient means for achieving microscopic imaging with resolution below the diffraction limit. Microscale LEDs are already poised to have a transformative impact on display technology, but it remains challenging to construct arrays of individually controllable LEDs at the nanometer scale. Daria Bezshlyakh of the Technische Universitat Braunschweig in Germany and colleagues have developed a fabrication approach that enabled them to manufacture a compact super-resolution imaging system based on such arrays. Their device employs gallium nitride nano-LEDs that generate precisely structured patterns of illumination, which make it possible to image specimens at spatial resolutions smaller than the wavelength of light. Based on the performance and stability of this initial prototype, the authors conclude that similar devices could offer a promising platform for future molecular imaging applications.