Semiconductor Nanowire Light‐Emitting Diodes Grown on Metal: A Direction Toward Large‐Scale Fabrication of Nanowire Devices

Abstract

Bottom-up nanowires are attractive for realizing semiconductor devices with extreme heterostructures because strain relaxation through the nanowire sidewalls allows the combination of highly lattice mismatched materials without creating dislocations. The resulting nanowires are used to fabricate light-emitting diodes (LEDs), lasers, solar cells, and sensors. However, expensive single crystalline substrates are commonly used as substrates for nanowire heterostructures as well as for epitaxial devices, which limits the manufacturability of nanowire devices. Here, nanowire LEDs directly grown and electrically integrated on metal are demonstrated. Optical and structural measurements reveal high-quality, vertically aligned GaN nanowires on molybdenum and titanium films. Transmission electron microscopy confirms the composition variation in the polarization-graded AlGaN nanowire LEDs. Blue to green electroluminescence is observed from InGaN quantum well active regions, while GaN active regions exhibit ultraviolet emission. These results demonstrate a pathway for large-scale fabrication of solid state lighting and optoelectronics on metal foils or sheets.

Magnetron Sputter Epitaxy of High-Quality GaN Nanorods on Functional and Cost-Effective Templates/Substrates

“…Although the tendency is to form NRs with a similar diameter as the previous sample, the sample is characterized by NRs with irregular shapes and sizes, which resulted from the pronounced coalescence. Previous reports of GaN NRs grown on Mo films attribute the tilted growth and coalescence to the rough metal surface underneath [13,14]. On SiC (Figure 5c) the resulting growth is comparable to growth on Si.…”

Tunnel junction enhanced nanowire ultraviolet light emitting diodes

“…Wavelength tunable multiple AlGaN quantum disks are inserted at the center of the nanowire separated by AlN barriers to serve as the active region. To make a p-type electrical contact at the bottom of the nanowires these doubly graded heterostructures are grown on p-type Si or high work function metals [9], [13], [15]. As shown in the energy band diagram ( Fig.…”

Recent Advances on p-Type III-Nitride Nanowires by Molecular Beam Epitaxy

“…Moreover, their optical qualities seem to be not compromised, e.g., InN and GaN nanowires grown on silicon oxide show similar photoluminescence characteristics compared to the nanowires grown on Si [99]. Recently, visible and UV LEDs with InGaN and AlGaN quantum wells/quantum disks have been demonstrated on metal substrates [102][103][104][105][106]. III-nitride nanowire structures on graphene have also been investigated.…”