Research Interests

Research in Semiconductor Nanomaterials and Nano-photonics

• Experimental and Theoretical investigations of the two-dimensional waveguide modes in monolayer transition metal dichalcogenide nanostructures, and other novel optical phenomena, such as photonic Fano resonances in suspended atomic monolayers.
• Designed and constructed Raman and photoluminescence spectroscopy systems to perform laser spectroscopy measurements. Conducted optical spectroscopy analysis of various semiconductor nanostructures such as zinc oxide nanorods and gallium nitride nanowires, carbon nanotubes and diamond-like carbons etc. Investigated the near-field optical properties and morphology of semiconductor nanomaterials via scanning-near-field-optic-microscopy and atomic force microscopy.
• Investigated optical and electrical characterizations of wide-band-gap semiconductor thin-films and microelectronic devices such as gallium nitride field-effect-transistor, Schottky diode and zinc oxide thin-films using micro-Raman and photoluminescence spectroscopy, photocurrent measurements, I-V and C-V characteristics.

Development of Novel Optical Imaging and Signal Analysis Modalities

• Develop dynamic laser speckle imaging modality to investigate blood flows in micro-vascular vessels and other biological activities in tissues and cell aggregates. Explore novel optical signal analysis methods, especially the frequency-domain statistical methods, for the more efficient processing of the big data generated by complex systems.
• Investigated the plasmonic resonance in the colloidal suspensions of metallic nanoparticles. Designed and constructed a dynamic light scattering instrument to study the microrheology of the nanoparticles in the polymer composite matrices.

Publications

• Dake Wang, “The Most Energy Efficient Way to Charge the Capacitor in a RC Circuit”, Physics Education. Vol. 52, pp. 065019 (2017).
• Xingwang Zhang, Shinhyuk Choi, Dake Wang, Carl Naylor, Charlie Johnson and Ertugrul Cubukcu, “Unidirectional Doubly Enhanced MoS2 Emission via Photonic Fano Resonances”, Nano Lett. 17 (11), pp 6715–6720 (2017).
• D. Wang, and J. Ranger, “The spectral maps of dynamic speckle patterns: a new perspective to look at the motion-induced spatiotemporal cross-correlation”, Volume 345, 99–104, Optics Communications, (2015).
• D. Wang, and H. Khan, “Understanding the Thermal Efficiencies of Heat Engines: a Graphical Approach”, Physics Education, Vol. 48, pp. 169 (2013).
• D. Wang, A. Moyer, and M. Henderson, “The Intensity Fluctuation Spectra of Dynamic Laser Speckle Patterns Acquired by a Full-field Temporal Modulation Method”, Applied Optics, Vol. 51, Issue 31, pp. 7576-7580 (2012).
• D. Wang, "The Reciprocal Relation of Mutual Inductance in a Coupled Circuit System," American Journal of Physics, Article in Press (2012)
• D. Wang, and N. Reynolds, "Photoluminescence of Zinc Oxide Nanowires: The Effect of Surface Band Bending, " ISRN Condensed Matter Physics, (2011), Article ID 950354, doi:10.5402/2012/950354
• D. Wang, K. Mittauer and N. Reynolds, "Raman Scattering of Carbon Disulfide: the Temperature Effect," American Journal of Physics, Vol. 77, Issue 12, pp. 1130-1134 (2009) A-J. Cheng, Y-H. Tzeng, H. Xu, S. Alur, Y.Q. Wang, M. Park, T-H. Wu, C. Shannon, D-J. Kim, and D. Wang, "Raman Analysis of Longitudinal Optical Phonon-Plasmon Coupled Modes of Aligned ZnO Nanorods," Journal of Applied Physics, Vol. 105, Issue 7, pp. 073104 (2009)
• N. Sathitsuksanoh, D. Wang, H-Y. Yang, Y. Lu, and M. Park, "Structural and Optical Properties of Encapsulated ZnO in Porous Host Matrix," Acta Materialia, Vol. 58, Issue 2, pp. 373-378 (2009)
• Y. Zhou, C. Ahyi, T. I.-Smith, M. BozackC. C. Tin, J. Williams, M. Park, A-J. Cheng, D. Kim, J.-H. Park, D. Wang, A. Hanser, E. A. Preble, N. M. Williams, and K. Evans, "Formation, etching and electrical characterization of thermally grown gallium oxide on the Ga-face of a bulk GaN substrate," Solid State Electronics, vol. 52, no5, pp. 756-764 (2008)
• A-J. Cheng, Y. Tzeng, Y. Zhou, M. Park, T-H. Wu, C. Shannon, D. Wang, and W. Lee "Thermal chemical vapor deposition growth of zinc oxide nanostructures for dye-sensitized solar cell fabrication,"Appl. Phys. Lett. 92, 092113 (2008) S. H. Choi, D. Wang, J. R. Williams, M. Park, W. Lu, S. Dhar and L. C. Feldman, "Nitridation of the SiO2/4H-SiC interface studied by surface-enhanced Raman spectroscopy," Applied Surface Science 253, 5411 (2007)
• Y. Zhou, D. Wang, C. Ahyi, C-C. Tin, J. Williams, M. Park, N. M. Williams, A. Hanser, "Temperature-dependent electrical characteristics of bulk GaN Schottky rectifier," Journal of Applied Physics. 101, 024506 (2007)
• A-J. Cheng, D. Wang, M. Park, and Y. Tzeng, "Visible luminescence from ZnO nanostructures," Mater. Res. Soc. Symp. Proc. 957, (2007) 0957-K07-39
• J. Huang, R. Seelaboyina, D. H. Kim, W. B. Choi, D. Wang and M. Park, "Catalyst effect on carbon nanotube branching," Diamond and Related Materials 16, 1524 (2007)
• Y. Zhou, C. Ahyi, C-C. Tin, J. Williams, M. Park, D-J. Kim, A-J. Cheng, D. Wang and A. Hanser, E. A. Preble, N. M. Williams, and K. Evans, "Fabrication and device characteristics of Schottky-type bulk GaN-based 'visible-blind' UV photodetectors," Applied Physics Letter 90, 121118 (2007)
• D. Wang, H. W. Seo, Y. Tzeng, C.-C. Tin, M. J. Bozack, J. R. Williams, M. Park, "Lasing in whispering gallery mode in ZnO nanonails," Journal of Applied Physics, 99, 093112 (2006). (Selected for inclusion in the June 5, 2006 issue of Virtual Journal of Nanoscale Science & Technology)
• D. Wang, N. Sathitsuksanoh, A-J. Cheng, Y. H. Tzeng, H. W. Seo, C.-C. Tin, M. J. Bozack, J. R. Williams, and M. Park, "Effects of post-growth annealing treatment on the photoluminescence of ZnO Nanorods," Journal of Applied Physics, 99, 113509 (2006)
• D. Wang, M. Park, Y. N. Saripalli, M. A. L. Johnson, C. Zeng, D. W. Barlage and J. P. Long, "Optical spectroscopic analysis of selected area epitaxially re-grown n+ GaN," Journal of Applied Physics, 99, 123106 (2006)
• Y. Zhou, D. Wang, C Ahyi, Chin-Che Tin, John Williams, Minseo Park, N. Mark Williams and Andrew Hanser, "High breakdown voltage Schottky rectifier fabricated on bulk n-GaN substrate," Solid-State Electronics,† 50, 1744 (2006)
• A-J. Cheng, D. Wang, H. W. Seo, C. Liu, M. Park, and Y. Tzeng, "Cold Cathodes for Applications in Poor Vacuum and Low Pressure Gas Environments: Carbon Nanotubes versus ZnO Nanoneedles," Diamond and Related Materials 15, 426 (2006)
• Y. Zhou, M. Li, D. Wang, C. Ahyi, C.-C. Tin, J. R. Williams, M. Park, N. M. Williams and A. Hanser, "Electrical characteristics of bulk GaN-based Schottky rectifiers with ultrafast reverse recovery," Applied Physics Letters 88, 113509 (2006)
• J. Park, J. Moon, H. Shin, D. Wang, and M. Park, "Direct-write fabrication of colloidal photonic crystal microarrays by ink-jet printing," Journal of Colloid and Interface Science 298(2), 713 (2006)
• D. Wang, C.-C. Tin, J. R. Williams, M. Park, Y. S. Park, C. M. Park, T. W. Kang and W.-C. Yang, "Raman scattering of self-assembled gallium nitride nanorods synthesized by plasma-assisted molecular beam epitaxy," Mater. Res. Soc. Symp. Proc. 892, FF11-03.1 (2006)
• D. Wang, M. Park, J. Park and J. Moon, "Reflectance spectroscopy of single photonic crystal island fabricated by ink-jet printing," Mater. Res. Soc. Symp. Proc. 901, Ra16-10.1 (2006)
• D. Wang, C.-C. Tin, J. R. Williams, M. Park, Y. S. Park, C. M. Park, T. W. Kang, and W.-C. Yang, "Raman characterization of electronic properties of self-assembled GaN nanorods grown by plasma-assisted molecular beam epitaxy," Applied Physics Letter 87, 242105 (2005)
• D. Wang, M. Park, J. Park, J. Moon, "Optical properties of single droplet of photonic crystal assembled by ink-jet printing," Applied Physics Letter 86, 241114 (2005). (Selected for inclusion in the June 20, 2005 issue of Virtual Journal of Nanoscale Science & Technology)
• H. W. Seo, D. Wang, Y. Tzeng, N. Sathitsuksanoh, C. C. Tin, M. J. Bozack, J. R. Williams, and M. Park, "Growth and Characterization of ZnO Nanonail," Mater. Res. Soc. Symp. Proc. 829, B2.26 (2005)

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