Role of growth temperature on formation of single crystalline GaN nanorods on flexible titanium foil by laser molecular beam epitaxy

Effect of surface modification and laser repetition rate on growth, structural, electronic and optical properties of GaN nanorods on flexible Ti metal foil

“…These ndings disclose the effect of laser repetition rate on the surface morphology of GaN nanostructures on nitridated Ti metal foils and a moderate repetition rate of 20 Hz is found to promote the growth of oriented GaN nanorods with a high areal density. Comparing with our previous studies, it is noted that the density of GaN nanorods on pre-nitridated Ti foils increased about one order with the increase of pre-nitridation temperature from 700 to 850 C. 21,24 The crystalline structure of the LMBE grown GaN nanostructures on nitridated Ti foil at different laser repetition rates and Ti foil substrate were characterized using 2q XRD scan and it is presented in Fig. 2(a).…”

“…Since the stoichiometric GaN target was ablated in the presence of additional nitrogen-plasma, it is likely to be N-rich growth condition. 21,23 At the low ux rate, initially GaN adatom or cluster nucleates randomly at grains and/or grain boundaries on the Ti metal foil and further changed to spherical-shaped 3D islands. As growth proceeds, the rate of new nucleation becomes less and the impinging ux prefers to grow on the existing GaN islands or clusters.…”

“…Recently, thin metal foils are being considered as alternate exible substrates for the growth of GaN nanowires because of their excellent thermal and electrical conductivities along with a high optical reectance, which open up unique possibilities of developing exible GaN based devices. 20,21 A few groups have recently reported the growth of GaN nanowires on Ti and Ta foils using PA-MBE at growth temperature of 730-800 C. 12,13 Here, Ti metal foil has an added advantage as it can serve as the direct bottom contact to GaN. The growth of GaN nanowires on exible and reactive metal foils at relatively high growth temperature of 800 C using conventional MBE process may lead to the formation of unwanted interfacial alloys or compounds.…”

Effects of experimental parameters on the growth of GaN nanowires on Ti-film/Si(1 0 0) and Ti-foil by molecular beam epitaxy

“…The use of metallic substrates can be beneficial for some optoelectronic applications due to specific properties of metals such as efficient thermal conductivity, and charge carrier extraction. A few recent studies reported the growth of GaN nanowires on Ti-films [11,12] and foils [13][14][15][16][17][18]. In most of these studies, a TiN layer was prepared before growing GaN nanowires [11][12][13][14][16][17][18].…”

“…A few recent studies reported the growth of GaN nanowires on Ti-films [11,12] and foils [13][14][15][16][17][18]. In most of these studies, a TiN layer was prepared before growing GaN nanowires [11][12][13][14][16][17][18]. While a TiN layer is not intentionally prepared before growing nanowires, it may form during the growth of GaN from the reaction between impinging N and Ti on the substrate.…”