Spiral Deposition with Alternating Indium Composition in Growing an InGaN Nanoneedle with the Vapor-Liquid-Solid Growth Mode

Wen-Ming Chang,Chieh Hsieh,Tsung-Yi Tang,Che‐Hao Liao ,Yean‐Woei Kiang ,Chih-Yen Chen ,C C Yang

doi:10.1155/2012/653195

Abstract

The spiral deposition of InGaN with a quasiperiodical distribution of indium content along the growth direction for forming InGaN nanoneedles (NNs) with the vapor-liquid-solid (VLS) growth mode is demonstrated. The VLS growth is implemented by using Au nanoparticles (NPs) as the catalyst in metalorganic chemical vapor deposition. The Au NPs on a GaN template are generated through pulsed laser irradiation. The observation of spiral deposition is based on the analyses of the scanning results in the high angle annular dark field and energy dispersive X-ray measurements of transmission electron microscopy. In the measurements, the composition variations along and perpendicular to the growth direction (thec-axis) are illustrated. The alternating indium content along the growth direction is attributed to a quasiperiodically pulsed behavior of indium supersaturation process in the melted Au NP at the top of an InGaN NN. The spiral deposition of InGaN is due to the formation of an NN at the location of an Au NP with a screw-type dislocation beneath in the GaN template, at which the growth of a quasi-one-dimensional structure can be easily initiated.

Highlights

Quasi-one-dimensional (1D) semiconductor structures have attracted much attention for their potential applications to efficient optoelectronics devices, including light-emitting diode and solar cell
The sphere-like Au NPs for serving as the catalyst are prepared on a 2 μm GaN template, which is grown at 1000◦C on c-plane sapphire substrate with metalorganic chemical vapor deposition (MOCVD)
The observation was based on the analyses of the high angle annular dark field (HAADF) and energy dispersive X-ray (EDX) scanning results along and perpendicular to the growth direction

Summary

Introduction

Quasi-one-dimensional (1D) semiconductor structures have attracted much attention for their potential applications to efficient optoelectronics devices, including light-emitting diode and solar cell. In the area of wide-band-gap nitride, self-organized GaN nanorods (NRs) (or called nanowires or nanocolumns) have been widely grown on sapphire and silicon substrates with molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD) With this growth method, GaN NRs can be formed from certain nucleation centers in an AlN or SiNx buffer layer. In a quasi-1D structure, because the strain can be relaxed in the lateral dimension such that the strain energy can be released to avoid the phase separation behavior, the growth of a high-indium InGaN compound becomes feasible. The extrinsiccatalyst VLS mode is an attractive method for growing an InGaN quasi-1D structure For such a growth process, Au NPs have been used as the catalyst.

InGaN Nanoneedle Growth Conditions and Basic Characterization Results

Analyses of Transmission Electron Microscopy Images

Discussions

Findings

Conclusions