Radial growth behavior and characteristics of m-plane In _0.16Ga_0.84N/GaN MQW nanowires by MOCVD

We demonstrate the growth of high-quality non-polar (m-plane) and semi-polar (r-plane) multiple quantum well (MQW) nanowires (NWs) for high internal quantum efficiency optoelectronic device applications. Highly aligned InGaN/GaN MQW layers were grown radially on the {1-100} sidewalls of c-axis n-GaN NWs on Si(111) substrates by pulsed flow metalorganic chemical vapor deposition (MOCVD) technique. The photoluminescence (PL) measurements revealed that the wavelength and intensity of the MQW structure with various pairs (5 to 20) were observed to be very stable and easily controlled with indium concentration. The cathodoluminescence (CL) spectrum of individual InGaN/GaN MQW NWs is dominated by the band-edge emission at 369 and 440 nm with a relatively homogeneous profile of parallel alignment. High-resolution transmission electron microscopy (HR-TEM) studies of radial InGaN/GaN MQW NWs measured along <0001> and <2-1-10> zone axes revealed that the grown NWs were uniform with six non-polar m-plane facets without any dislocations and stacking faults. This kind of high-quality radial NWs are viable high surface area MQW structures for the enhanced efficiency of light emitting diodes.