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Johnny C. Ho, Ph.D.


Associate Professor

    Contact Information:

    Department of Physics and Materials Science,
    City University of Hong Kong
    Tat Chee Avenue,
    Hong Kong SAR, China.
    Tel: +852-34424897
    Fax: +852-34420538
    Email: johnnyho@cityu.edu.hk

    Group Website
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    Ho photo 


    Dr. Johnny Ho obtained his B.S. in chemical engineering with high honors from the University of California at Berkeley in 2002. Before attending graduate school, he worked as a process engineer at National Semiconductor in Silicon Valley. He then received his M.S. and Ph.D. in materials science and engineering from the University of California at Berkeley in 2005 and 2009, respectively, specializing in the topic of design of nano-materials for next-generation electronics under the supervision of Professor Ali Javey in electrical engineering. Before beginning his academic position at City University of Hong Kong, he performed studies on energy-harvesting devices as a post-doctoral fellow at Lawrence Livermore National Laboratory, California. His research interest is highly interdisciplinary involving chemistry, physics, materials science and various engineering disciplines to explore novel nano-materials and nano-engineering techniques for technological applications.


    Research Interests:

    - Monolayer Assisted Nano-Scale Processing

    Device scaling has been the driving force for technology advancements in the semiconductor industry over the last few decades. This scaling presents a tremendous challenge to fabricate nano-scale devices controllably and cost-effectively. In this regard, we aim to explore the manipulation of the surface properties of semiconductor nanostructures to enable alternative and novel nano-scale device fabrication schemes.

    - Synthesis and Characterization of Fundamental Properties of Nano-Materials

    Recently, nano-materials have attracted a large amount of research attention due to the unique physical properties of materials at the nano-scale. We are interested in developing new synthesis techniques to enable new functionalities of nano-materials. At the same time, it is essential to study and understand the fundamental properties of the materials in order to tailor them for technological applications.    

    - Large-Scale and Heterogeneous Integration of Nano-Materials for Flexible and High Performance Technological Applications

    Although numerous amazing properties of nano-materials such as nanowires (NW) have been reported, the controlled and uniform assembly of ¡§bottom-up¡¨ NW materials with high scalability is still one of the significant bottleneck challenges to integrate NWs for practical technological applications. In this regard, we have achieved a high throughput and generic printing approach to assemble NWs on any substrate including Si, plastics, paper, and glass. With this approach, nano-materials based electronic, energy-harvesting, photonic and sensor applications will be explored.

    Selected Publications:


    • Takei K., Takahashi T., Ho J.C., Ko H., Gillies A.G., Leu P.W., Fearing R.S., Javey A. "Nanowire active matrix circuitry for low-voltage macro-scale artificial skin", Nature Materials, 9, 821-826, 2010.

    • Ho J.C., Ford A.C., Leu P.W., Chueh Y.L., Javey A. ¡§Formation of Ultra-Shallow Junctions in Indium Arsenide with Monolayer Doping¡¨, Applied Physics Letter, 95, 072108, 2009.
    • Fan Z., Razavi H., Do J.W., Moriwaki A., Ergen O., Chueh Y.L., Leu P.W., Ho J.C., Takahashi T., Reichertz L.A., Brown G.F., Neale S., Yu K., Wu M., Ager J.W., Wu J., Javey A. ¡§Three Dimensional Nanopillar Array Photovoltaics on Low Cost and Flexible Substrates¡¨, Nature Materials, 8, 648-653, 2009.

    • Fan Z., Ho J.C., Takahashi T., Yerushalmi R., Takei K., Chueh Y.L., Javey A. ¡§Towards the Development of Printable Nanowire Electronics and Sensors¡¨, Advanced Materials, 21, 3730-3743, 2009.

    • Ho J.C., Yerushalmi R., Smith G., Majhi P., Bennett J., Halim J., Faifer V.N., Javey A. ¡§Wafer-Scale, Sub-5 nm Junction Formation by Monolayer Doping and Conventional Spike Annealing¡¨, Nano Letters, 9, 725¡V730, 2009.

    • Ford A.C.*, Ho J.C.*, Chueh Y.L.*, Tseng Y.C., Fan Z., Guo J., Bokor J., Javey A. ¡§Diameter-Dependent Electron Mobility of InAs Nanowires¡¨, Nano Letters, 9, 360-365, 2009.

    • Fan Z.*, Ho J.C.*, Jacobson Z., Razavi H., Javey A. ¡§Large Scale, Heterogeneous Integration of Nanowire Arrays for Image Sensor Circuitry¡¨, Proceedings of the National Academy of Sciences (PNAS), 105, 11066-11070, 2008.

    • Ho J.C.*, Yerushalmi R.*, Jacobson Z.A., Fan Z., Alley R.L., Javey A. ¡§Controlled Nanoscale Doping of Semiconductors via Molecular Monolayers¡¨, Nature Materials, 7, 62-67, 2008.

    • Fan Z., Ho J.C., Jacobson Z.A., Yerushalmi R., Alley R.L., Razavi H., Javey A. "Wafer-Scale Assembly of Highly Ordered Semiconductor Nanowire Array by Contact Printing", Nano Letters, 8, 20-25, 2008. [Cover Article].

    •  Ho J.C., Specht P., Yang Q., Xu X., Hao D., Weber E.R. ¡§Effects of Stoichiometry on Electrical, Optical, and Structural Properties of Indium Nitride¡¨, Journal of Applied Physics, 98, 93712-1-5 (2005).


    Intel Foundation Ph.D. Fellowship, U.S.A. (2007 ¡V 2009)

    Openings (Postdoctoral Fellow, Graduate Student, Research Assistant Positions Available):

    Since the nature of our research programs is highly interdisciplinary, bridging chemistry, physics, materials science and various engineering disciplines, all the lab members will have the opportunities to be exposed to and master a broad spectrum of fundamental and technical knowledge in the synthesis, characterization, assembly, device fabrication and integration of nanostructured materials for technological applications. Students will also learn project management and presentation proficiency. This skill set is essential for future success in both the academic and industrial environments. All talented and enthusiastic individuals with strong academic backgrounds are encouraged to apply.

    Interested applicants should send their CV via emails to <johnnyho@cityu.edu.hk>.

    Group Website:

    Ho Research Group for Nano-Materials and Nano-Engineering Laboratory