Highlight Publications

1. S. R. Tamalampudi,J.-Y. Lu*, N. Rajput, C. Y. Lai, B. Alfakes, R. Sankar, ... & M. Chiesa*, "Superposition of Semiconductor and Semi-metal Properties of Self-assembled 2D SnTiS3 Heterostructures," npj 2D Materials and Applications, vol. 4, no. 23, July. 2020 (IF ~ 9.324)
2. J.-Y. Lu, Q. Ge, A. Raza, and T. J. Zhang*, "Quantum Mechanical Prediction of Wettability of Multiphase Fluids–Solid Systems at Elevated Temperature," Journal of Physical Chemistry C, vol. 123, no. 20, pp. 12753-12761, May. 2019 (IF ~ 4.309)(highlighted in Emirates News)
3. J.-Y. Lu, T. A. Olukan, S. R. Tamalampudi, A. Al-Hagri, C.-Y. Lai, M. A. Almahri, H. Apostoleris, I. Almansouri, and M. Chiesa*, "Insights into Graphene Wettability Transparency by Locally Probing its Surface Free Energy," Nanoscale, 11, pp. 7944-7951, Mar. 2019 (IF ~ 6.98)
4. X. Q. Li, J. L. Li, J.-Y. Lu, N. Xu, C. L. Chen, X. Z. Min, B. Zhu, H. X. Li, L. Zhou, S. N. Zhu, T. J. Zhang, and J. Zhu*, "Enhancement of Interfacial Solar Vapor Generation by Environmental Energy," Joule, vol. 2, no. 7, pp. 1331-1338, Jul. 2018 (IF ~ 15.04)
5. J.-Y. Lu, Q. Ge, H. Li, A. Raza, and T. J. Zhang*, "Direct Prediction of Calcite Surface Wettability with First-Principles Quantum Simulation," Journal of Physical Chemistry Letters, vol. 8, no. 21, pp. 5309-5316, Oct. 2017 (IF ~ 7.33)(highlighted in Emirates News)
6. J.-Y. Lu, A. Raza, S. Noorulla, Afra S. Alketbi, N. X. Fang, G. Chen, and T. J. Zhang*, "Near-Perfect Ultrathin Nanocomposite Absorber with Self-Formed Topping Plasmonic Nanoparticles," Advanced Optical Materials, 5, 1700222, Jul. 2017 (IF ~ 7.12)(highted in UAE News)
7. J.-Y. Lu, S. H. Nam, K. Wilke, A. Raza, Y. K. Lee, A. A. Ghaferi, N. X. Fang, and T. J. Zhang*, "Localized Surface Plasmon Enhanced Ultrathin Film Broad-Band Nanoporous Absorbers," Advanced Optical Materials, vol. 4, no. 8, pp. 1255-1264, May 2016 (IF ~ 7.12)(highlighted in MIT News)

The following are the full list of publications

2D Materials Studies

An ultra-clean interface between graphene and the III-V substrate is required to maintain lattice match for the growth of the single-crystalline of MOCVD deposition, which enables the substrate to be still “observable” from the top thin film deposition. Here, we propose combining bimodal AFM, micro-Raman spectroscopy, and DFT AFM to locally probe surface energy properties on the graphene-coated substrate. In addition to providing quantitative insight into the surface interactions of complicated graphene coatings, this work demonstrates a new route to nondestructively monitor the interface between graphene and coated substrates. The related work has been published in "Nanoscale," which could be accessed here.

The following figure shows that the surface energy of graphene coated substrate produced through exfoliation of natural graphite flakes and chemical vapor deposition are different.

Surface Wettability Studies

A general quantum mechanical approach to predict the macroscopic wettability of any solid crystal surfaces for different liquids directly through atomic-level density functional simulation. As a benchmark, the wetting characteristics of calcite crystal (10.4) under different types of fluids (water, hexane, and mercury), including either contact angle or spreading coefficient, are predicted and further validated with experimental measurements. This approach has been extended to liquid/liquid/solid multiphase systems, several physics quantities, such as the macroscopic contact angles, the work of adhesion at the solid-liquid interface, and the interfacial tension at the liquid-liquid interfaces, can be simultaneously predicted through density functional theory simulation. This opens a new avenue to probe the mechanism of sophisticated wetting phenomena in multiphase systems with direct quantum mechanical simulation. to provides insightful and quantitative predictions of complicated surface wettability alteration problems and wetting behaviors of liquid/liquid/solid triphase systems. The related work has been published in "Journal of Physical Chemistry Letter," which could be accessed here.

The following figure shows that an atomic methodology to directly predict macroscopic contact angle of liquid droplet on crystal substrates.

Interfacial Solar Vapor Generators

For solar steam generation application, the solar absorber coating needs to be integrated into devices for maximizing their efficiency, the structure design can be utilized with Multiphysics solar/thermal simulations. In this work, we analyze the structural designs and evaluate how much environmental energy can be exploited to enhance the performance of an interfacial solar vapor generation device, under various light intensities. This realization has direct implications in various important processes, particularly for wastewater treatment. The related work has been published in "Joule," which could be accessed here.

The following figure shows that Measured and simulated temperature distributions of the vapor generator under three different light intensities.

Plasmonic Nanocomposite Solar Absorbers

Finite difference time domain optical simulation method can provide a guide to design the nanohole and nanocomposite structures, which is potentially an absorptive coating for the high-performance solar absorber. In combination with optical simulation results, a class of scalable ultrathin silver/SiO2 nanocomposite films with self-formed topping plasmonic nanoparticles is designed and fabricated. We experimentally and theoretically demonstrate that just by controlling the high throughput co-sputtering process, the nanocomposite absorbers can achieve near 100% light absorption in the wavelength ranges from 300 to 800 nm. The related work has been published in "Advanced Optical Materials," which could be accessed here.

The following figure shows that Nanocomposites, consisting of metallic nanoparticles embedding in a dielectric host, can significantly enhance light-matter interactions in solar energy conversion and optical applications.

Plasmon Enhanced Nanoporous Absorbers

Ultrathin semiconductor films have attracted much attention due to their strong interference persisting inside the lossy dielectric film on a reflective substrate. We proposed a plasmon-enhanced ultrathin film broadband absorber by combining the ultrathin film absorber with localized surface plasmon resonances. This concept can be realized by patterning nanoholes on an absorber comprised of an absorptive ultrathin Ge film and a reflective Au layer, where the localized surface plasmon mode is activated by metallic pore-shaped holes. The related work has been published in "Advanced Optical Materials," which could be accessed here. The proposed plasmonic broadband ultrathin film absorber can be applied in many applications, such as solar vapor generation,photovoltaics, and solar water splitting.

The following figure shows that a plasmon-enhanced ultrathin film broadband absorber is proposed by combining the ultrathin lossy film absorber with localized surface plasmon resonances, which are activated by pore-shape plasmon resonances.

Finite difference time domain method

In 1966, Kane Yee [1] proposed the finite difference time domain (FDTD) method, which is Maxwell’s curl equations based on the central finite difference method. In the 1990s, the FDTD method has become one of primary optical simulation methods owing to the implementation of the perfectly matched layer (PML) technique, which effectively truncate computational regions in the simulation domain. Nowadays, with advanced computational capabilities, the FDTD method has become a robust tool for the analysis and design of optical devices for various applications in daily routines at both academic and industrial levels. An excellent textbook of the FDTD method was written by Taflove et al [2] and can be used as a user manual.

Here, I provide a two-dimensional TE FDTD code employing the PML absorption boundary condiction and total/scattering fields for your reference. In this code, the interaction of EM waves with a core-shell nanocylinder can be visualized as a function fo time. The permittivities of shell and core are 4 and 1, respectively. The simulation domain consists of total field, scattered field, and perfectly matched layer (PML), as shown in the below figure. The Matlab code could be accessed here.

1. Kane Yee (1966). "Numerical solution of initial boundary value problems involving Maxwell's equations in isotropic media". IEEE Transactions on Antennas and Propagation vol. 14, no. 3, pp. 302–307.
2. Allen Taflove and Susan C. Hagness (2005). Computational Electrodynamics: The Finite-Difference Time-Domain Method, 3rd ed. Artech House Publishers. ISBN 978-1-58053-832-9.

Plasmonic Metal Nanoparticles

Over the last two decades, plasmon resonances in metallic nanoparticles have been the subject of intense research efforts. Owing to having high efficiency at absorbing and scattering light, applications related to plasmonic metal nanoparticles are impressively numerous, ranging from sensing to solar vapor generating to biological cell imaging. Here, I provide a 2D-TE FDTD code for calculations of extinction, scattering, and absorption efficiencies of a gold-shell dielectric-core nanocylinder, as shown in the below figure (a). The Fortran code could be accessed here.

It would be nice to have a analytical solution to verify the simulation results of a 2D-FDTD codes. Therefore, I also provide a analytical code for calculating the extinction spectrum of a core-shell nanocylinder. The calculation results of a gold-shell dielectric-core nanocylinder, with an outer radius of 50 nm and an inner radius of 40 nm, are compared to those of FDTD simulations, as shown in the below figure (b). The code can be accessed here.

Application of the spectral density function to composite materials

According to the Bergman spectral density theory, any effective medium model has an integral representation in terms of a spectral density function g(x) that depends on the geometry of the composite meterial and is independent of the optical constants of individual component materials. Therefore, conneting the spectral density function to the effective optical constant provides a great oppotunity to measure the contribution of individual and percolated particles inside the nanocomposite.

• update 12/04/2020

THANK YOU ALL!

• My beloved family

Thank you for all the supports during my postdoc career:

• Prof. TieJun Zhang, Khalifa University
• Prof. Daniel Choi, Khalifa University
• Prof. Matteo Chiesa, Khalifa University
• Prof. Ibraheem Almansouri, Abu Dhabi Future Energy Company
• Prof. Nicholas Xuanlai Fang, MIT
• Prof. Gang Chen, MIT
• Prof. Thomas C.-K, Yang, National Taipei University of Technology
• Prof. Weilin Yang, Jiangnan University
• Dr. Aikifa Raza, Khalifa University
• Dr. Hongxia Li, Khalifa University
• Dr. Srinivasa Reddy Tamalampudi, Khalifa University
• Dr. Nitul S Rajput, Khalifa University
• Dr. Shih-Wen Chen, National Taipei University of Technology
• Mr. Boulos Fakes, Khalifa University
• Mr. Abdulrahman Al-Hagri, Khalifa University
• Ms Chia-Yun Lai, Khalifa University
• Ms Mariam Ali Almahri, Khalifa University
• Mr. Harry Apostoleris, Khalifa University
• Mr. Yu-Cheng Chiou, UiT
• Mr. Cheng-Hsiang Chiu, UiT
• Ms Shabnam Ranny, Aspen Heights School

Thank you for the supports during my PhD:

• Prof. Yuan-Huei Chang, my PhD advisor
• Prof. Chi-Te Liang, Nationa Taiwan University
• Prof. Yang-Fang Chen, National Taiwan University
• Prof. Kuo-PIn Chiu, CYCU
• Prof. Chih-Ming Wang, NCU
• Prof. Din-Pin Tsai, Academia Sinica
• Prof. Wei Chih Liu, NTNU
• Dr. Husan-Yi Chao, SCIENTEK
• Dr. Hung-Ji Huang, Instrument Technology Research Center
• Dr. Ryan Cheng, senior member at my lab

Thank you for the supports during my career at TSMC:

• Dr. Lu-Hsing Tsai, TSMC
• Dr. Chung-Liang Cheng, TSMC
• Mr. Wilson Liu, ASML
• Ms. Ya-Ling Huang, TSMC
• Mr. Che-Chih Hsu, TSMC
• Dr. San-Yi Huang, TSMC
• Dr. Ju-Ying Chen, TSMC

Khalifa University

As a tutor in the following areas:

TSMC

As a teaching group leader in:

National Taiwan University

As a teaching assistant in the following two courses: