VPD GROUP

The natural evolution of functional materials’ architecture calls for their confinement in spatial and dimensional modes. Dimensional constraint arises from the ubiquitous need for materials to be confined to zero (i.e., dots), one (lines), and two (i.e., films/membranes) dimensions to enhance aerial density and possible novel properties.

We synthesize and characterize emerging 2D layered materials, including the doped and alloyed chalcogenides. In particular, we study the structure property relationship of M_IM_IIP₂X₆ (M_I = transition metal cation, X = S, Se) for next generation nanoelectronics. Integration of layers into heterostructures and multi-dimensional nanocomposites such as core-shell structures offer exciting new opportunities for synergistic coupling of disparate phenomena. Silicon core-MoS₂ shell structures are analyzed for improved light-matter interaction in optical applications. We are also interested in optimizing the performance of thermoelectric materials, and work is done to elucidate the underlying principles of their formation and properties. Work is also being done to study the structure-optical property relationships in ternary chalcogenides systems to optimize the synthesis of all-inorganic photovoltaics. Through collaborations with industry leaders such as Rigetti Computing, recent efforts have also focused on improving the coherence of superconducting transmon qubits for next-generation quantum computers.

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Embedded in these initiatives are varied in-situ and ex-situ characterization, using photon, phonon, ion, scanning probe and electron microscopy. This is a multi/interdisciplinary effort done in collaboration with groups throughout NU Materials Science and Engineering, Physics and Astronomy, Electrical Engineering & Computer Science, Chemistry, and Applied Physics. 

Representative Publications:

• Probing the Optical Responses and Local Dielectric Functions of an Unconventional Si@MoS₂ Core-Shell Architecture. Nano Lett. 2022, 22, 4848-4853.
• Realizing Resonance Couplings in Si@MoS₂ Core-Shell Architectures. Small, 2022, 2200413.
• Vapor-Liquid Assisted Chemical Vapor Deposition of Cu₂X Materials. 2D Mater. 2022, 9 (4), 045013.
• Synthesis of Layered vs Planar Mo₂C: Role of Mo Diffusion. 2D Mater. 2022, 9 (1), 015039.
• High Thermoelectric Performance in Chalcopyrite Cu1-xAgxGaTe2-ZnTe: Nontrivial Band Structure and Dynamic Doping Effect.  Am. Chem. Soc.2022, 144, 20, 9113–9125.
• Tuning the Structural and Magnetic Properties in Mixed Cation Mn_xCo_2–xP₂S₆. Inorg. Chem. 2022, XXXX, XXX, XXX-XXX.
• Mixed Metal Thiophosphate Fe2–xCoxP2S6: Role of Structural Evolution and Anisotropy. Inorg. Chem. 2021, 60, 22, 17268–17275.
• Grovogui, J. A., Slade, T. J., Hao, S., Wolverton, C., Kanatzidis, M. G., & Dravid, V. P. (2021). Implications of doping on microstructure, processing, and thermoelectric performance: The case of PbSe. Journal of Materials Research, 36(6), 1272-1284. doi:10.1557/s43578-021-00130-8
• Cai, S., Hao, S., Luo, Z.-Z., Li, X., Hadar, I., Bailey, T. P., . . . Kanatzidis, M. G. (2020). Discordant nature of Cd in PbSe: off-centering and core–shell nanoscale CdSe precipitates lead to high thermoelectric performance. Energy & Environmental Science, 13(1), 200-211. doi:10.1039/c9ee03087e
• Zhang, X., Hao, S., Tan, G., Hu, X., Roth, E. W., Kanatzidis, M. G., . . . Dravid, V. P. (2019). Ion Beam Induced Artifacts in Lead-Based Chalcogenides. Microscopy and Microanalysis, 25(4), 831-839. doi:10.1017/s1431927619000503