Molecular beam epitaxy (MBE) for light-emitting applications is an innovative technology that will change the way we understand and use light.

Tien Khee is currently researching into molecular beam epitaxy (MBE) grown group-III nitride based quantum structures for light-emitting applications at KAUST. He has authored, co-authored and delivered more than 200 journal articles, invited talks, and conference articles receiving over 4000 citations. He is the center manager and one of the co-principal investigators for KACST Technology Innovation Center (TIC) for Solid State Lighting at KAUST. He received his Ph.D. in electrical and electronics engineering from Nanyang Technological University (NTU), Singapore, investigating on molecular beam epitaxy (MBE) grown small bandgap nitride semiconductor. His M.Eng. research in the same laboratory focused on electron cyclotron resonance plasma etching of As-based and P-based III-V semiconductor for eventual applications in heterojunction bipolar transistors. Serving the scientific community, he contributed as reviewers for various international journals, such as:

  • ACS Nano Letters
  • ACS Advanced Functional Materials
  • Scientific Reports
  • RSC Nanoscale
  • Applied Nanoscience
  • Journal of the Electrochemical Society
  • Journal of Crystal Growth
  • Nanotechnology
  • Photonics Technology Letters
  • Photonics Journal
  • Optics Letters
  • Superlattices and Microstructures
  • Applied Physics Letters
Tien Khee also serves as:
  • Vice President, IEEE Photonics Chapter, Western Saudi Arabia Section, 2019.
  • Associate Editor, Encyclopedia of Applied Physics, Wiley-VCH, 2018-2019.
  • Guest Editor, Journal of Nanophotonics, Society of Photo-Optical Instrumentation Engineers (SPIE), 2018.

As a Principal Research Scientist, he co-advises Ph.D. / Masters students working on MBE-grown 2D quantum well and 3D nanowires emitters for broad gain, short-reach communication NIR laser diodes, low polarization field nitride LEDs and laser diodes, laser-based smart solid-state lighting, and emitters epitaxy transfer onto conductive and/or flexible substrates. The long-term research goal targets the realization of narrow linewidth emitters, and wide-band nitride emitters spanning UV-blue-far red-NIR wavelengths.

As the manager of the photonics laboratory, he involved in the early establishment of the laboratory, and currently overseeing new capability establishment, laboratory operational continuity, as well as internal and external research collaboration. He was also involved as a co-mentor for the Saudi-RSI Summer Internship Program in KAUST.

Prior to this in 2007-2009, he embarked upon a research fellow position at NTU conducting research into MBE grown GaAs nanowires, quantum-dots structures and dilute-nitride-antimonide solar cells using SiGe- and Si-based heterogeneous substrates.

Previously in 2004-2006, he worked as an engineer for Tinggi Technologies, a start-up company in Singapore designing and fabricating high power GaN blue LEDs on highly conductive substrates. Tien Khee later served as a member of technical staff and as thin film process manager in the same company.

Research Interests

  • Fundamental understanding of Molecular Beam Epitaxy grown nanostructures and heterostructures. (Significant achievement: surface treatment of nanowires for light emission, water splitting and piezo-phototronic effects, without which nanowires could not be properly developed.)
  • Exploration of hybrid semiconductor nanostructure integration and semiconductor growth on unconventional substrates using Molecular Beam Epitaxy. (Demonstration of semiconductor and 2-dimensional materials integration as well as nanowires growth on metal, silicon and transparent-conductive substrates.)
  • Design of reconfigurable epitaxy system for realization of single-crystal hybrid oxide/semiconductor heterostructures. 
  • Tunable wavelength, broad-band and single-line light-emitters based on conventional group-III nitride quantum-well and group-III arsenide quantum-dash devices. (The applied research based investigations targets compact and portable system in various cross-discipline utility.)
  • Laser and light-emitting diodes for terrestrial and underwater communications. (Proof of principles demonstration of optical wireless communication under the influence of channel turbulence, and explore the boundaries for the mitigating methodologies and technology implementation.)
  • Laser-based indoor horticulture. (Significant achievement: successful laser-environment-chamber implementation and completion of a proof-of-concept growth cycle.)

Selected Publications

Highlight of selected research articles (over 100 journal articles) in underwater optical wireless communications, lasers and superluminescent devices, nanowires light-emitting diodes on a new metal platform, novel 4D imaging characterization of the effect of passivation on nanowires’ surface-states, materials and devices in the UV-Visible-near-infrared.

ORCID 0000-0002-1480-6975  |  Scopus Author ID 7402229824  | ResearcherID C-3213-2016

  1. (Editorial) Tien Khee Ng, and Jianchang Yan, "Special Section Guest Editorial: Semiconductor UV Photonics", Journal of Nanophotonics, 12(4), 043501 (2018).

  2. (Invited Commentary) Boon S. Ooi, Meiwei Kong, and Tien Khee Ng, "Underwater wireless optical communications: opportunity, challenges and future prospects", Progress in Quantum Electronics, 73, Article No. 100275 (2020).

  3. (Review Article) Hassan M. Oubei, Chao Shen, Abla Kammoun, Emna Zedini, Ki-Hong Park, Xiaobin Sun, Guangyu Liu, Chun Hong Kang, Tien Khee Ng, Mohamed-Slim Alouini, and Boon S. Ooi, "Light based underwater wireless communications", Japanese Journal of Applied Physics, 57(8S2), 08PA06, 1-18 (2018).

  4. (Review Article) Mohd Sharizal Alias, Malleswararao Tangi, Jorge A. Holguin-Lerma, Mohammad Khaled Shakfa, Edgars Stegenburgs, Abdullah A. Alatawi, Islam Ashry, Ram Chandra Subedi, Davide Priante, Tien Khee Ng, Boon S. Ooi, "Review of nanophotonics approaches using nanostructures and nanofabrication for III-nitrides UV photonic devices", Journal of Nanophotonics, 12(4), 043508, 1-56  (2018).

  5. (Review Article) Chao Zhao, Nasir Alfaraj, Ram Chandra Subedi, Jian Wei Liang, Abdullah A. Alatawi, Abdullah A. Alhamoud, Mohamed Ebaid, Mohd Sharizal Alias, Tien Khee Ng*, and Boon S. Ooi*, "III-nitride nanowires on unconventional substrates: From materials to optoelectronic device applications", Progress in Quantum Electronics, 61, 1-31 (2018). *Corresponding authors.

  6. (Review Article) Jung-Wook Min, Davide Priante, Malleswararao Tangi, Guangyu Liu, Chun Hong Kang, Aditya Prabaswara, Chao Zhao, Latifah Al-Maghrabi, Yazeed Alaskar, Abdulrahman M. Albadri, Ahmed Y. Alyamani, Tien Khee Ng*, and Boon S. Ooi*, "Unleashing the potential of molecular beam epitaxy grown AlGaN-based ultraviolet-spectrum nanowires devices", Journal of Nanophotonics, 12(4), 043511, 1-38 (2018).  *Corresponding authors.​

  7. Chao Zhao#, Tien Khee Ng#, Nini Wei, Aditya Prabaswara, Mohd Sharizal Alias, Bilal Janjua, Chao Shen, and Boon S. Ooi, "Quantum-disks-in-Nanowires on Bulk-Metal Substrates for High-power Light-emitters", Nano Letters, 16 (2), pp. 1056-1063 (2016). # Equal contribution authors.

  8. Chao Zhao#, Tien Khee Ng#, Rami T. ElAfandy, Aditya Prabaswara, Giuseppe Bernardo Consiglio, Idris A. Ajia, Iman S. Roqan, Bilal Janjua, Chao Shen, Jessica Eid, Ahmed Y. Alyamani, Munir M. El-Desouki, and Boon S. Ooi, “Droop-Free, Reliable, and High-Power InGaN/GaN Nanowire Light-Emitting Diodes for Monolithic Metal-Optoelectronics”, Nano Letters, 16(7), pp. 4616-4623 (2016). # Equal contribution authors.

  9. Mohamed Ebaid, Davide Priante, Guangyu Liu, Chao Zhao, Mohd Sharizal Alias, Ulrich Buttner, Tien Khee Ng, Tayirjan Taylor Isimjan, Hicham Idriss, and Boon S. Ooi, Unbiased photocatalytic hydrogen generation from pure water on stable Ir-treated In0.33Ga0.67N nanorods, Nano Energy, 37, 158-167 (2017).

    • (Articles 6-8) The first demonstration of facile formation of ultra-long-wavelength nanowires-LEDs on bulk metal that enhances light extraction, lowers resistance, and enhances light extraction in single MBE growth run; and utilization of the semiconductor-nanowires/metal technology platform for hydrogen fuel generation. Patent applications submitted.

  10. Chao Zhao, Tien Khee Ng, Aditya Prabaswara, Michele Conroy, Shafat Jahangir, Thomas Frost, John O'Connell, Justin D. Holmes, Peter J. Parbrook, Pallab Bhattacharya, and Boon S. Ooi", An enhanced surface passivation effect in InGaN/GaN disk-in-nanowire light emitting diodes for mitigating Shockley–Read–Hall recombination", Nanoscale, 7, 16658-16665 (2015).

  11. Riya Bose, Jingya Sun, Jafar I. Khan, Basamat S. Shaheen, Aniruddha Adhikari, Tien Khee Ng, Victor M. Burlakov, Manas R. Parida, Davide Priante, Alain Goriely, Boon S. Ooi, Osman M. Bakr, and Omar F. Mohammed, "Spatial and Temporal Imaging of Energy Loss and Carrier Diffusion in InGaN Nanowires using Scanning Ultrafast Electron Microscopy", Advanced Materials, (2016).

  12. Jafar I. Khan, Aniruddha Adhikari, Jingya Sun, Davide Priante, Riya Bose, Basamat S. Shaheen, Chao Zhao, Tien Khee Ng, Osman M. Bakr, Boon S. Ooi, Omar F. Mohammed, "Enhanced Optoelectronic Performance of a Passivated Nanowire-based Device: Key Information from Real-space Imaging using 4D Electron Microscopy", Small (2016).

    • Articles 9-11: These 3 articles showcase the first demonstration of nitride-nanowires optical device improvement by facile chemical-passivation of nanowires, and confirmation of origin of device improvement (mitigated the effect of Shockley-Read-Hall non-radiative recombination) using advanced spectroscopy with femtosecond temporal resolution, and nanometer spatial resolution.

  13. Chao Shen, Tien Khee Ng, John T. Leonard, Arash Pourhashemi, Hassan M. Oubei, Mohd S. Alias, Shuji Nakamura, Steven P. DenBaars, James S. Speck, Ahmed Y. Alyamani, Munir M. Eldesouki, and Boon S. Ooi, “High-modulation-efficiency, integrated waveguide modulator-laser diode at 448 nm”, ACS Photonics (2016).

    • The first low-power, gigahertz bandwidth waveguide-modulator seamlessly integrated on semipolar (20/2/1) laser diodes.

  14. Chao Shen, Tien Khee Ng, Changmin Lee, Shuji Nakamura, James S. Speck, Steven P. DenBaars, Ahmed Y. Alyamani, Munir M. El-Desouki, and Boon S. Ooi, "Semipolar InGaN quantum-well laser diode with integrated amplifier for visible light communications", Optics Express, 26(6), A219-A226 (2018).

  15. Chao Shen, Changmin Lee, Edgars Stegenburgs, Jorge Holguin Lerma, Tien Khee Ng, Shuji Nakamura, Steven P. DenBaars, Ahmed Y. Alyamani, Munir M. El-Desouki, and Boon S. Ooi, "Semipolar III-nitride quantum well waveguide photodetector integrated with laser diode for on-chip photonic system", Applied Physics Express, 10(4), 042201, 1-3 (2017).

  16. Chao Shen, Tien Khee Ng, John T. Leonard, Arash Pourhashemi, Shuji Nakamure, Steven P. DenBaars, James S. Speck, Ahmed Y. Alyamani, Munir M. El-desouki, and Boon S. Ooi, "High-brightness semipolar (20/2/1) blue InGaN/GaN superluminescent diodes for droop-free solid-state lighting and visible-light communications" Optics Letters (2016).

    • Article 12-15: The first demonstration of semipolar laser diodes with integrated amplifier or waveguide photodetector. High-power, > 700-MHz modulation-bandwidth superluminescent-diode was also demonstrated for efficiency-droop-free, and speckle-free white laser illumination and communication.

  17. Hassan M. Oubei, Jose R. Duran, Bilal Janjua, Huai-Yung Wang, Cheng-Ting Tsai, Yu-Cheih Chi, Tien Khee Ng, Hao-Chung Kuo, Jr-Hau He, Mohamed-Slim Alouini, Gong-Ru Lin, and Boon S. Ooi, “4.8 Gbit/s 16-QAM-OFDM transmission based on compact 450-nm laser for underwater wireless optical communication”, Optics Express, 23(18), 23302-23309 (2015); Nature Photonics 9, 707 (2015).

  18. Hassan Makine Oubei, Changping Li, Ki-Hong Park, Tien Khee Ng, Mohamed-Slim Alouini, and Boon S. Ooi, “2.3 Gbit/s underwater wireless optical communications using directly modulated 520 nm laser diode”, Optics Express, 23(16), 20743-20748 (2015).

    • Article 16-17: Article 16 was featured in Nature Photonics article "Optical communications: Underwater link”: record 4.8 Gbit/s transmission rate underwater optical communications (UWOC) for deep sea exploration and sensing, for eventual integration with the existing sonar-based communication system. Article 17 provides an alternate straightforward On/Off keying scheme in providing high bit-rate transmission in coastal water using green (520-nm) laser.

  19. Bilal Janjua, Hassan M. Oubei, Jose R. Durán Retamal, Tien Khee Ng, Cheng-Ting Tsai, Huai-Yung Wang, Yu-Chieh Chi, Hao-Chung Kuo, Gong-Ru Lin, Jr-Hau He, and Boon S. Ooi, “Going beyond 4 Gbps data rate by employing RGB laser diodes for visible light communication”, Optics Express, 23(14), 18746-18753 (2015).

    • Mercury-free green light-source development. The red-green-blue lasers are used for simultaneous implementation of solid-state lighting and >4 Gbit/s visible light communications.

  20. D. Priante, I. Dursun, M. S. Alias, D. Shi, V. A. Melnikov, T. K. Ng, O. F. Mohammed, O. M. Bakr, and B. S. Ooi, “The recombination mechanisms leading to amplified spontaneous emission at the true-green wavelength in CH3NH3PbBr3 perovskites”, Applied Physics Letters, 106, 081902 (2015).
    • Applied Physics Letters is a journal in the Nature Index list. The article provides the physical explanations of the amplified spontaneous emission mechanisms in optically pumped MAPbBr3 perovskite device emitting at the true-green, eye-sensitive wavelength of 555 nm.
    • Top 25 Most-download APL article in 2015.
  21. Mohammed Zahed Mustafa Khan, Tien Khee Ng, and Boon S. Ooi, “Self-assembled InAs/InP quantum dots and quantum dashes: Material structures and devices”, Progress in Quantum Electronics, 38(6), 237-313 (2014).
    • Review paper on physical insights, device characterization, and optical telecommunications applications of quantum dash based lasers and superluminescent diode.​

Professional Memberships

  • Fellow of the Institution of Engineering and Technology, FIET.
  • Fellow of the Institute of Physics, FInstP.
  • Senior Member of IEEE (Photonics Society, and Electron Devices Society).
  • Senior Member of The Optical Society (OSA).
  • July 2020 – present: Principal Research Scientist, Photonics Laboratory, KAUST, KSA.
  • Jun 2016 – July 2020: Senior Research Scientist, Photonics Laboratory, KAUST, KSA.
  • Aug 2012 – Jun 2016: Research Scientist, Photonics Laboratory, KAUST, KSA.
  • Oct 2009 – Jul 2012: Assistant Research Scientist, Photonics Laboratory, KAUST, KSA.
  • Jan 2007 – Aug 2009: Research Fellow, Cleanroom & Characterization Laboratory, NTU, Singapore.
  • Aug 2004 – Nov 2006: Member of Technical Staff & Process Manager, Tinggi Technologies, Singapore.
  • July 2002 – July 2004: Singapore-MIT Research Associate, Cleanroom & Characterization Lab., NTU, Singapore.
  • Jun 97 – Nov 98: Test Engineer, Hewlett-Packard, Singapore.

Education Profile

  • 2005 - Ph.D. Electrical and Electronic Engineering, Nanyang Technological University (NTU), Singapore.
  • 2001 - M.Eng. Electrical and Electronic Engineering, Nanyang Technological University (NTU), Singapore.