Nonpolar GaAs Nanowires Catalyzed by Cu₅As₂: Insights into As Layer Epitaxy

Abstract

Controlled synthesis of GaAs nanowires (NWs) with specific phases and orientations is important and challenging, which determines their electronic performances. Herein, single-crystalline GaAs NWs are successfully synthesized by using complementary metal-oxide semiconductor compatible Cu2O catalysts via chemical vapor deposition at an optimized temperature of 560 °C. In contrast to typically Au catalyzed GaAs NWs, the Cu2O catalyzed ones are found to grow along nonpolar orientations of zincblende <110> and <211> and wurtzite <1̅100> and <2̅110>. The Cu2O catalysts are found to change into orthorhombic Cu5As2 after the NW growth, which is also significantly distinguished from the Au–Ga catalyst alloy in the literature. The Cu5As2 alloy plays the epitaxy role in the nonpolar GaAs NW growth due to the lattice matching with the nonpolar planes of GaAs, which is verified by the atomic stack model. These nonpolar oriented GaAs NWs have minimized stacking faults, promising for the other semiconductor synthesis as well as electronic applications.

Low-Temperature As-Doped In2O3 Nanowires for Room Temperature NO2 Gas Sensing

“…It is obvious that v is inversely proportional to T , leading to a low growth rate of In 2 O 3 NWs. On the other hand, higher temperature accelerates the diffusion of “As” into the catalyst to form the Cu–As alloy, which improves the performance of the catalyst. ,, Hence, the most appropriate growth temperature is determined by these two factors. Notably, the most favorable growth temperature is fixed at 600 °C, which is relatively lower for the synthesis of In 2 O 3 NWs as compared in Table .…”

“…First, the group III element is dissolved in the metal catalysts, and then, it reacts with the oxygen elements in the gas phase to form NWs. Hence, the type and concentration ratio of the group III/catalyst determine the dissolution and precipitation rate of the group III elements and the reaction rate with the oxygen elements, and recently, many studies have discovered the metal catalysts’ effect on inducing the uniform growth of the NWs. − However, at present, metal film by physical thermal evaporation or purchased metal particle sol is mostly used, which is limited to the thickness of the film or the size of the particles. − In addition, metal ions are often selected as dopants in In 2 O 3 , such as “Sr”- and ‘Sn”-doped In 2 O 3 to enhance the electrical performance, , while there is less study on the effect of negative ion substituting oxygen ions.…”

Insights into the Synthesis Mechanisms of Ag-Cu3P-GaP Multicomponent Nanoparticles

“…During the last decades, the metal-assisted growth of semiconductor nanostructures has developed as a promising tool enabling high control over crystal properties, including crystal structure, − composition, − growth direction, − morphology, ,, surface faceting, − doping profile, − and defect structure. − The seed material’s role was limited to the capability to nucleate and selectively grow the semiconductor nanocrystal. − Few reports considered the seed material as an active component of the synthesized nanostructure. − We propose that the metal-assisted growth approach is promising for synthesizing advanced multicomponent nanostructures. Therefore, a deeper understanding of the involved formation mechanisms is essential to exploit its full potential.…”

“…During the last decades, the metal-assisted growth of semiconductor nanostructures has developed as a promising tool enabling high control over crystal properties, including crystal structure, 42 − 44 composition, 45 − 47 growth direction, 48 − 50 morphology, 48 , 51 , 52 surface faceting, 53 − 55 doping profile, 56 − 58 and defect structure. 59 − 61 The seed material’s role was limited to the capability to nucleate and selectively grow the semiconductor nanocrystal.…”