Site-specific growth of Zno nanorods using catalysis-driven molecular-beam epitaxy

Abstract

We report on catalyst-driven molecular beam epitaxy of ZnO nanorods. The process is site specific, as single crystal ZnO nanorod growth is realized via nucleation on Ag films or islands that are deposited on a SiO2-terminated Si substrate surface. Growth occurs at substrate temperatures on the order of 300–500 °C. The nanorods are uniform cylinders, exhibiting diameters of 15–40 nm and lengths in excess of 1 μm. With this approach, nanorod placement can be predefined via location of metal catalyst islands or particles. This, coupled with the relatively low growth temperatures needed, suggests that ZnO nanorods could be integrated on device platforms for numerous applications, including chemical sensors and nanoelectronics.

One-dimensional ZnO nanostructures: Solution growth and functional properties

“…It has been demonstrated to have enormous applications in electronic, optoelectronic, electrochemical, and electromechanical devices [3][4][5][6][7][8], such as ultraviolet (UV) lasers [9,10], light-emitting diodes [11], field emission devices [12][13][14], high performance nanosensors [15][16][17], solar cells [18][19][20][21], piezoelectric nanogenerators [22][23][24], and nanopiezotronics [25][26][27]. One-dimensional (1D) ZnO nanostructures have been synthesized by a wide range of techniques, such as wet chemical methods [28][29][30], physical vapor deposition [31][32][33], metal-organic chemical vapor deposition (MOCVD) [34][35][36], molecular beam epitaxy (MBE) [37], pulsed laser deposition [38,39], sputtering [40], flux methods [41], eletrospinning [42][43][44], and even top-down approaches by etching [45]. Among those techniques, physical vapor deposition and flux methods usually require high temperature, and easily incorporate catalysts or impurities into the...…”

Controlled epitaxial growth modes of ZnO nanostructures using different substrate crystal planes

“…By utilizing such epitaxial growth modes and depending on the crystal orientation of the substrate, it becomes possible to design surface morphologies for individual nanostructures. This approach is distinct from other position-controlled growth techniques 21 that employ patterned metal catalysts [22][23][24] or catalyst-free amorphous growth masks. 25,26 Furthermore, when compared with other methods of fabricating inorganic nanotubes, 27 such as those that utilize selective etching of core materials in core-shell heterostructure nanowires 28 or interfacial solid-state diffusion between core-shell nanowires, 29 the epitaxial growth method demonstrated here provides a rational route that avoids unintentional damage or contamination during etching or diffusion.…”

ZnO Nanorods Arrays and Heterostructures for the High Sensitive UV Photodetection

“…ZnO NRs with controlled shape and order could be grown by thermal vapor deposition (TVD) (Huang et al, 2001b;Giri et al, 2010;Li et al, 2008;Yao et al, 2002), metal-organic chemical vapor deposition (Yuan & Zhang, 2004;Park et al, 2002;Kim et al, 2009), molecular beam epitaxy (Heo et al, 2002), hydrothermal/solvothermal methods (Breedon et al, 2009;Verges et al, 1990;Alvi et al, 2010;Tak & Yong, 2005;Pacholski et al, 2002;Song & Lim, 2007) and top down approach by etching (Wu et al, 2004). Among those techniques, vapor deposition and chemical methods are the widely used techniques for their versatility about controllability, repeatability, quality and mass production.…”