Large-scale fabrication and luminescence properties of GaN nanostructures by a soft UV-curing nanoimprint lithography

GaN nanorods with a period of 400 nm and diameter of 200 nm, and nano-gratings with a period of 400 nm and gap width of 100 nm are fabricated on wafers by a soft UV-curing nanoimprint lithography. These nanostructures show high periodicity and good morphology. The photoluminescence (PL) spectra exhibit that the integral PL intensity of GaN nanorods is enhanced as much as 2.5 times, compared to that of as-grown GaN films. According to finite-difference time-domain simulations and cathodoluminescence mappings, it is concluded that the enhancement for nanorods is due to the improvements of both spontaneous emission rate and light extraction efficiency caused by periodic GaN structures on the surface. By identifying the Raman shift of E1(TO) and E2(H) modes of GaN films with nano-gratings and nanorods, the normal-plane strain ε(zz) is determined. The PL emission energy is found to be proportional to the ε(zz), whose linear proportionality factor is calculated to be -27 meV GPa(-1).

[1]  Tao Wang,et al.  Influence of strain relaxation on the optical properties of InGaN/GaN multiple quantum well nanorods , 2011 .

[2]  J. Baek,et al.  Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes , 2011 .

[3]  J. Zúñiga-Pérez,et al.  Fabrication and properties of etched GaN nanorods , 2012 .

[4]  Hiroshi Harima,et al.  TOPICAL REVIEW: Properties of GaN and related compounds studied by means of Raman scattering , 2002 .

[5]  Denis L. Rousseau,et al.  First-Order Raman Effect in Wurtzite-Type Crystals , 1969 .

[6]  Jonathan J. Wierer,et al.  III -nitride photonic-crystal light-emitting diodes with high extraction efficiency , 2009 .

[7]  L. J. Guo,et al.  Nanoimprint Lithography: Methods and Material Requirements , 2007 .

[8]  Z. Mi,et al.  Controlling electron overflow in phosphor-free InGaN/GaN nanowire white light-emitting diodes. , 2012, Nano letters.

[9]  S. Gwo,et al.  InGaN/GaN nanorod array white light-emitting diode , 2010 .

[10]  L. J. Wang,et al.  The fabrication of GaN-based nanopillar light-emitting diodes , 2010 .

[11]  Kyeong Jae Byeon,et al.  Recent progress in direct patterning technologies based on nano-imprint lithography , 2012 .

[12]  Tao Wang,et al.  Characterization of InGaN-based nanorod light emitting diodes with different indium compositions , 2012 .

[13]  Christopher C. S. Chan,et al.  Optical studies of the surface effects from the luminescence of single GaN/InGaN nanorod light emitting diodes fabricated on a wafer scale , 2013 .

[14]  Y. Kiang,et al.  Geometry and composition comparisons between c-plane disc-like and m-plane core-shell InGaN/GaN quantum wells in a nitride nanorod. , 2012, Optics express.

[15]  Karen Willcox,et al.  Kinetics and kinematics for translational motions in microgravity during parabolic flight. , 2009, Aviation, space, and environmental medicine.

[16]  A. I. Zhmakin Enhancement of light extraction from light emitting diodes , 2011 .

[17]  Henri Benisty,et al.  Photonic crystal laser lift-off GaN light-emitting diodes , 2006 .

[18]  A. Vijayaraghavan,et al.  Directed self-assembly of block copolymers for use in bit patterned media fabrication , 2013 .

[19]  Hui Song,et al.  A crossbar-type high sensitivity ultraviolet photodetector array based on a one hole–one nanorod configuration via nanoimprint lithography , 2011, Nanotechnology.

[20]  Chun-Hsiang Chang,et al.  High performance InGaN/GaN nanorod light emitting diode arrays fabricated by nanosphere lithography and chemical mechanical polishing processes. , 2010, Optics express.

[21]  Lei Wang,et al.  Hybrid nanoimprint-soft lithography with sub-15 nm resolution. , 2009, Nano letters.

[22]  N. Peyghambarian,et al.  Printed sub-100 nm polymer-derived ceramic structures. , 2013, ACS applied materials & interfaces.

[23]  M. Funato,et al.  Optical properties of InGaN/GaN nanopillars fabricated by postgrowth chemically assisted ion beam etching , 2010 .

[24]  A. N. Smirnov,et al.  Raman and photoluminescence studies of biaxial strain in GaN epitaxial layers grown on 6H–SiC , 1997 .

[25]  Heon Lee,et al.  Fabrication of SiNx-based photonic crystals on GaN-based LED devices with patterned sapphire substrate by nanoimprint lithography. , 2012, Optics express.

[26]  Theresa S. Mayer,et al.  Fabrication of two-dimensional photonic crystals using interference lithography and electrodeposition of CdSe , 2001 .

[27]  Jonathan J. Wierer,et al.  III-nitride core–shell nanowire arrayed solar cells , 2012, Nanotechnology.

[28]  Tao Wang,et al.  Enhancement in solar hydrogen generation efficiency using a GaN-based nanorod structure , 2013 .

[29]  Anuj R. Madaria,et al.  Toward optimized light utilization in nanowire arrays using scalable nanosphere lithography and selected area growth. , 2012, Nano letters.

[30]  R. Dupuis,et al.  Control of Quantum-Confined Stark Effect in InGaN-Based Quantum Wells , 2009, IEEE Journal of Selected Topics in Quantum Electronics.

[31]  Nanoimprinting by Melt Processing: An Easy Technique to Fabricate Versatile Nanostructures , 2011, Advanced materials.

[32]  Hong Yee Low,et al.  Direct patterning of TiO₂ using step-and-flash imprint lithography. , 2012, ACS nano.

[33]  Hong Jiang,et al.  Realization of a High‐Performance GaN UV Detector by Nanoplasmonic Enhancement , 2012, Advanced materials.

[34]  A. Waag,et al.  GaN based nanorods for solid state lighting , 2012 .