Vertical GaN Nanowires and Nanoscale Light-Emitting-Diode Arrays for Lighting and Sensing Applications

For various lighting and monolithic sensor systems application, vertically aligned three-dimensional (3D) gallium nitride (GaN)- and indium gallium nitride (InGaN)/GaN-based LED nanowire arrays with sub-200 nm feature sizes (down to 35 nm) were fabricated using a nanosphere liftoff lithography (NSLL) technique combined with hybrid top down etching (i.e., inductively coupled plasma dry reactive ion etching (ICP-DRIE) and wet chemical etching). Owing to the lithographic opening and well-controlled surface functionalization prior to the polystyrene nanosphere (PN) deposition, vertical GaN nanowire arrays with an area density of 9.74 X 10(8) cm(-2) and an aspect ratio of >10 could be realized in a specified large area of 1.5 X 1.5 mm(2). Optoelectrical characteristics of the nanoLEDs were further investigated in cathodoluminescence (CL) measurements, in which multiquantum well (MQW) shows a clear CL-emission at a wavelength of 465 nm. Thus, using NSLL to manufacture low-cost but highly ordered 3D GaN-based nanowires and nanoLEDs is a feasible alternative to other sophisticated but more expensive nanolithography methods.