Yeonjoon Park

Tel: +1 (757) 621-6112; Fax: +1 (757) 864-6326Park_Yeonjoon_bg

Research Interests

  • Solar and microwave powered aircrafts;
  • Electric propulsion and flight control;
  • Design and fabrication of optical micro-chips;
  • X-ray diffraction analysis of Aluminum super alloy;
  • Rhombohedral super-hetero epitaxy and defect engineering for semiconductor;
  • Non-linear electro-refractive optical material and device development;
  • Research on advanced thermo-electric materials;
  • Design and construction of semiconductor thin film growth chamber, RF-plasma sputtering machine;
  • III-V/Nitride Molecular Beam Epitaxy (MBE) growth of GaInNAs layers for 1.3 micron optical fiber communication laser diode applications;
  • Growth and characterization of wide band-gap III-nitride semiconductors;
  • Design and construction of Real-Time Vibration Compensating Secondary Electron Microscope (SEM) and in-situ electron beam lithography equipments; and
  • Advanced semiconductor characterization (X-ray diffraction, RHEED, LEED, STM/AFM, XPS/UPS, Scanning Auger, Photoluminescence, DLTS, ECV-Profile).


  • Ph.D. in Material Science & Mineral Engineering, University of California at Berkeley, 2003, Advanced semiconductor growth, processing and characterization
  • M.S. in Physics, Seoul National University (South Korea), 1996, Solid state experimental physics with Scanning Tunneling Microscope and XPS/UPS
  • B.S. in Physics, Seoul National University (South Korea), 1993

Current Research

Energy Harvesting Airships for Heavy Cargo Transportation: Working under NASA and DoT’s support, a team of researchers led by Park, is designing, fabricating, and flight-testing two airships, each powered by photovoltaic solar-cells and microwave receiver array. These power-harvesting airships instantaneously receive electric power from sun light during daytime, microwave during night time, and fly without any fuel or batteries. Park completed the overall 3D structure CAD design, electric propulsion system design and fabrication, flight-control avionics system design, as well as installation and programming.  This resulted in a series of successful flight demonstrations of the 20ft.-long solar airship and 6ft.-long microwave airship.  Park’s team at NASA Langley Research Center conducted the demonstrations in 2011. For these demonstrations, Park worked as an electric propulsion designer, control avionics programmer, and flight-test director who collaborated with NASA test-pilots, safety officers, fabrication teams and test measurement teams.  These prototype airships helped a systematic study for renewable-energy-based short-distance air-transportation of heavy trailer-cargos in strategically important barrier spots with low-to-medium traffic frequencies in 168,960 miles of US highway system and 1-million miles of secondary roads, in order to save an estimated multi-billion dollars of road and bridge construction cost. In 2007, the United States spent $670B/year to construct and maintain the highway system.

Fresnel Micro Spectrometer for Neural Probe Pin: This project aims to develop a tiny spectrometer chip, which has about 1mm3 of optical path volume. The conventional spectrometers are based on Fraunhofer diffraction, which cannot be miniaturized due to the critical length limit. When the optical axis is shortened smaller than the critical length, Fraunhofer diffraction turns invalid and Fresnel diffraction becomes valid. Since the new spectrometer chip is based on Fresnel diffraction, it can be miniaturized into a few hundred times smaller volume than that of the conventional spectrometer. NIA and NASA researchers are developing this ultra-small and lightweight integrated spectrometer chip for space exploration and medical applications, such as in-vivo optical monitoring inside a human brain.

SiGe Quantum-Well Solar Cells & Thermoelectric Materials: A super growth chamber has been designed and constructed to grow new semiconductor materials with atomic precision. Because many unprecedented semiconductor alloys and devices can be fabricated at NASA Langley Research Center, a team of researchers has set out to try to build a new hybrid crystal structure of cubic semiconductors and trigonal crystals. These will be used to build high efficiency quantum well solar cells and new thermoelectric materials. Park has invented a few new X-ray diffraction characterizations in the recent years. By combining new X-ray diffraction methods and ultra-high-precision, the super growth machine may open a new horizon of hundreds of unprecedented materials and devices.

Recent Publications

  • Active Patents
    • US 20090072078A1 New Configuration and Power Technology for Application-Specific Scenarios of High Altitude Airships
    • US 20080014621A1 Fabrication of Metal Nanoshells Derived by a Biotemplate
    • PCT/KR2008/002664, Deep Brain Stimulation Device Having Wireless Power Feeding By Magnetic Induction
    • US 7,769,135  X-ray diffraction wafer mapping method for rhombohedral super-hetero-epitaxy
    • US 7,558,371  Method of generating X-ray diffraction data for integral detection of twin defects in super-hetero-epitaxial materials
    • US 7,514,726  Graded index silicon geranium on lattice matched silicon geranium semiconductor alloy
    • US 7,510,802  Multilayer ferritin array for bio-nanobattery
    • US 7,379,231  Ferroelectric Light Control Device
    • US 7,375,808 B2 Dual Sensing Capable Germ or Toxic Chemical (GTC) Sensor using Quantum Aperture Array with Surface Plasmon Polariton (SPP)
    • US 7,341,883  Silicon germanium semiconductive alloy and method of fabricating same

60 NASA Langley Research Center Invention Disclosures (2003~2011)

Selected Publications

  • “SiGe finds a fantastic home on Sapphire”, Yeonjoon Park, Sang Choi, Compound Semiconductor April/May 2010, p.18 (2010)
  • “Versatile Smart Optical Material Characterization System”, Yeonjoon Park, SangJoon Park, Uhn Lee, Kunik Lee, Sang Choi, Proceedings of SPIE Conference on Smart Structures & Materials / NDE 2010, (2010)
  • “Perspective in Nanoneural Electronic Implants With Wireless Power-Feed and Sensory Control”, Uhn Lee, Kyo D. Song, Yeonjoon Park, Vijay K. Varadan, Sang Choi, Journal of Nanotechnology in Engineering and Medicine, May 2010 — Volume 1, Issue 2, 021007 (15 pages) doi:10.1115/1.4001413
  • “Nano-Scale Lateral Milling with Focused Ion Beam for Ultra-Smooth Optical Device Surface”,Yeonjoon Park, SangJoon Park, Uhn Lee, and Sang H. Choi,  Recent Patents on Space Technology, (2), p.51-58 (2010)
  • “Miniaturization of a Fresnel spectrometer”, Yeonjoon Park, Laura Koch, Kyo D Song, SangJoon Park, Glen King, and Sang Choi, Journal of Optics – A: Pure Applied Optics, 10 (2008) 095301
  • “Rhombohedral epitaxy of cubic SiGe on trigonal c-plane sapphire”, Yeonjoon Park, Glen C. King, Sang H. Choi, Journal of Crystal Growth 310 (2008) 2724–2731
  • “Diffraction analysis for periodic nano-scale apertures, scatterers and absorbers”,Yeonjoon Park, John D Wright, Jared D L Jensen, Glen C King, Sang H Choi, Meas. Sci. Technol. 16, p.2208–2212 (2005)
  • “Electrical and Optical Properties of Ferroelectric BaTiO3:Eu”, Yeonjoon Park, Alexander Grichener, Jacob Jensen, Sang H. Choi, Proc. of Photonics West Conference, SPIE Vol. 5728, p.68 (2005)
  • Presentations at 2nd World Congress, Biomimetics, Artificial Muscles & Nano-Bio 2004
  • Focused Ion Beam Processing of GaN Surface for VCSEL Mirror Growth
  • Diffraction Measurement of Periodic Sub-Wavelength Apertures
  • XRD Characterization of Ultra-Thin Electro-Optic Material Layers
  • BTA as a Molecular Bridge Material between Microelectronic Electrodes and Organic Polymers
  • “Direct Electron Beam Processing of Semiconductor Nanostructures”, Yeonjoon Park, Rian Zhao, Petra Specht, Eicke R. Weber, Proceedings of 2002 MRS Spring Meeting, R11.11 (2002)
  • “AFM study of lattice matched and strained InGaAsN layers on GaAs”, Yeonjoon Park, Michael J. Cich, Rian Zhao, Petra Specht, Henning Feick, Eicke R. Weber, Physica B 308-310, 98 (2001)
  • “High resolution x-ray diffraction strain-stress analysis of GaN/Sapphire heterostructures”, V. Harutyunyan, A.P. Aivazyan, E.R. Weber, Y. Kim, Y. Park and S.G. Subramanya, J. Physics D: Appl. Phys. 34, A35 (2001)
  • “Analysis of Twin Defects in GaAs(111)B MBE Growth”, Y. Park, M.J. Cich, R. Zhao, P. Specht, E.R. Weber, E. Stach, S. Nozaki, Journal of Vacuum Science and Technology B 18, 1566 (2000)
  • “Low temperature ultrahigh vacuum cross-sectional scanning tunneling microscope for luminescence measurements”, Yoonho Khang, Yeonjoon Park, M. Salmeron, E.R. Weber, Review of Scientific Instruments, Dec. 1999, vol.70, (no.12):4595-9 (1999)
  • “Electrical Characterization of Beryllium Doped Low Temperature MBE Grown GaAs”
    M.J. Cich, R. Zhao, Y. Park, P. Specht, E.R. Weber, in: Physik Mikrostrukturierter Halbleiter 10, eds.: P. Kiesel, S. Malzer, T. Marek, Erlangen-Nuernberg, p.85 (1999)
  • “Thickness dependent ultraviolet photoemission spectroscopy and scanning tunneling microscopy study of BTA molecular layers on Cu(110) “, Park Y, Noh H, Kuk Y, Cho K, Sakurai T, Journal of Korean Physical Society 29 (6), 745 (1996)


  • R&D 100 Award for Rhombohedral Super Hetero Epitaxy (2009, US)
  • Solar Industry Award for Metrics Innovation (2010, Europe)
  • Nine NASA LaRC Innovation Committee Board (ICB) Awards (2003~2010)
  • NASA Langley Appreciation for mentorship in LARSS program  (2005)



100 Exploration Way
Hampton, VA 23666