Motivation and Overview

1
ANN NIRT GOALI Nano-Engineering Efficient
Optoelectronic Devices NSF Grant ECS
0609416 PIs S. Nikishin, J. Berg, A. Bernussi,
M. Holtz, H. Temkin Nano Tech Center, Texas Tech
University, Lubbock TX-79409

• Motivation and Overview
• Develop and apply methods of nanoengineering to
  improve light extraction properties of
  ultraviolet light-emitting diodes (LEDs).
• The main efforts in year one were guided toward
• Nanoengineering of active region of UV LEDs
  using growth of AlGaN/AlGaN on AlGaN and AlN
  template substrates (GOALI partner TDI Inc.)
• Superlattices with AlGaN quantum dots in well
  material
• Detailed characterization of these materials
  using X-ray diffraction, photoluminescence,
  micro-cathodoluminescence, atomic force
  microscopy, and transmission electron
  microscopy
• Fabrication of nanophotonic surfaces on Si and
  GaN using nanolithography and plasma etching
• Study of optical properties and light extraction
  efficiency of nano-structured GaN substrates

Substrate design for improved epitaxy. (GOALI
partner TDI Inc.)
Plan-view 10 X 10 µm2 AFM scan of HVPE grown 6.4
µm thick AlN/sapphire template. The surface RMS
roughness is 3 nm. Step-flow growth
mode dominates.
X-ray reciprocal space map (RSM) for (0002)
reflection of AlN template. FWHM?-scan100"
FWHM2T-?110". Inset TEM cross-section of
AlN/sapphire interface.
Educational Impact This project provides nine
students at the BS, MS, and PhD levels with a
fully integrated multidisciplinary setting for
research and training. Of the students involved
in this work, five are female, and one of those
was African-American. Three senior researchers
are involved in research under this program.
Collaborators Technologies and Devices
International, Inc. Army Research Laboratory
Veeco Instruments, Inc. Soft-Impact, Ltd. The
Fox Group, Inc.
Select publications under this grant Transmission
properties of nanoscale aperture arrays in
metallic masks on optical fibers, J. Appl. Phys.
101, 014303 (2007). Selective area growth of GaN
nano islands by metal organic chemical vapor
deposition experiments and computer
simulations, Proc. Mat. Res. Soc. Symp., 955,
0955-I07 (2007). Enhanced luminescence from
AlxGa1-xN/ AlyGa1-yN quantum wells grown by gas
source molecular beam epitaxy with ammonia,
Proc. SPIE Photonics Conf., 6473, 647306 (2007).
X-ray diffraction study of AlN/AlGaN short
period superlattices, J. Appl. Phys., JR07-3866R
(2007). Deep UV light emitting diodes and solar
blind photodetectors grown by gas source
molecular beam epitaxy, J. Mater. Sci Mater
Electron, DOI 10.1007/s10854-007-9405-3
(2007). Luminescence properties of AlxGa1-xN
(0.4ltxlt0.5)/AlyGa1-yN (0.6lty1) quantum
structures grown by gas source molecular beam
epitaxy, physica status solidi c
(2007). Influence of photonic nanotexture on the
optical properties of GaN, Appl. Phys. Lett. 91,
103115 (2007).
50-mm AlN free standing wafer fabricated at TDI
Inc. HVPE growth of thick AlN layer on SiC
substrates and subsequent removal of the SiC
substrate by RIE. (Courtesy of TDI Inc.)