In the more recent years, more exotic substrates and catalytic growth methods have been investigated. Some of these include a study from 2012, which utilized a sapphire and amorphous quartz substrate with GaN growth catalyzed by gold nanoparticles. The team was able to control the diameter of the nanowires by controlling the diameter of the gold nanoparticle catalysts. \cite{Guadalupe_Carbajal_Ar_zaga_2012} A titanium layer grown on top of a sapphire layer has also been studied as a substrate for GaN growth, where the interaction between titanium and GaN results in extremely fast growth of 18 micrometers/minute for the nanowires. \cite{Rozhavskaya_2015} Another group utilized graphene, a one atom thick layer of double bonded carbon atoms, as a substrate for the nanowires. This is significant as graphene’s high electrical conductivity and flexibility may allow GaN nanowires to be incorporated into flexible devices in the future. \cite{Park_2014}

Further developments in fine-tuning the gallium source has led to the usage of Ga/GaCl3 instead of only molten gallium. This mixture of gallium compounds has demonstrated efficacy in forming much straighter nanowires compared to only molten gallium when grown on a silicon substrate. The same team also discovered that the rate of ammonia flow into the chamber enhances the reaction of gallium and nitrogen as well as the lateral growth rate. \cite{Ren_2014}

In 2014, a method to control the alignment of GaN nanowires grown via VLS was reported by the Kuykendall group. They utilized similar growth conditions as previously described, using trimethylgallium and ammonia as the feed gases, and nitrogen as the carrier gas. However, their unique gold-nickel bimetallic catalyst controlled the growth direction of the nanowires. By changing the molar ratio of the gold to nickel within the catalyst, they were able to select growth along different axes. It was observed that using more gold tilted the nanowires relative to the substrate, while using more nickel kept the nanowire growth perpendicular. The group was also able to change the direction of the nanowire in the middle of growth, with resulted in a bent shape. Furthermore, they reported that the growth resulted in defect-free nanowires up to diameters of 200 nm, which are much larger than previously reported diameters of 20-60 nm. \cite{Kuykendall_2014} Growth alignment has also been controlled through the structure of the substrate itself; reports of sapphire, quartz, and spinel substrates with different crystallographic orientations resulted in the nanowires growing at specific angles. \cite{Goren_Ruck_2014} \cite{Tsivion_2014} \cite{Tessarek_2014}

The shape of GaN nanowires has also been tuned by various syntheses, which had resulted in the creation of nanowires of serrated, helical, and branched formations. \cite{Li_2014} \cite{Suo_2015} Morphology control has been reported: for example, by controlling the presence of manganese, researchers were able to induce the formation of serrated nanowires. \cite{Patra_2014} However, even though the mechanisms behind these unique growth methods are not well understood, they have shown promise in unique applications for photochemistry and 3D nanostructures.