TY - JOUR

T1 - Evidence for dislocation induced spontaneous formation of GaN nanowalls and nanocolumns on bare C-plane sapphire

AU - Kesaria, Manoj

AU - Shetty, Satish

AU - Shivaprasad, S. M.

PY - 2011/9/15

Y1 - 2011/9/15

N2 - We demonstrate spontaneous growth of a high density of self-organized, oriented, and epitaxial GaN low-dimensional nanostructures on Al2O3(0001) by sheer kinetic control without involving lithography, catalysts, buffer layers, or any surface pretreatment and consequently reducing process steps. GaN thin films grown by plasma assisted-molecular beam epitaxy (PA-MBE) form wurtzite GaN as a nanowall hexagonal network of flat 2-D films. In a narrow parametric window, 1-D nanocolumns of high density (1 × 108 cm–2) with excellent structural and optical properties are observed. The reduced adatom diffusion in the high nitrogen rich conditions is proposed to cause supersaturation and nucleation at edge and screw dislocations, forming nanowalls and nanocolumns.

AB - We demonstrate spontaneous growth of a high density of self-organized, oriented, and epitaxial GaN low-dimensional nanostructures on Al2O3(0001) by sheer kinetic control without involving lithography, catalysts, buffer layers, or any surface pretreatment and consequently reducing process steps. GaN thin films grown by plasma assisted-molecular beam epitaxy (PA-MBE) form wurtzite GaN as a nanowall hexagonal network of flat 2-D films. In a narrow parametric window, 1-D nanocolumns of high density (1 × 108 cm–2) with excellent structural and optical properties are observed. The reduced adatom diffusion in the high nitrogen rich conditions is proposed to cause supersaturation and nucleation at edge and screw dislocations, forming nanowalls and nanocolumns.

U2 - 10.1021/cg200749w

DO - 10.1021/cg200749w

M3 - Journal article

VL - 11

SP - 4900

EP - 4903

JO - Crystal Growth and Design

JF - Crystal Growth and Design

SN - 1528-7483

IS - 11

ER -