AJINKYA SHINGOTE

AJINKYA SHINGOTE

Ph.D. Candidate in Physical & Materials Chemistry at the University of Notre Dame, USA

Research Interests

Broadly, I am interested in materials chemistry and optical spectroscopy, with a particular focus on designing materials for energy-related applications and probing their functionalities using custom-built optical characterization techniques. My current work focuses on probing strong exciton–plasmon coupling in metal–semiconductor hybrid structures via optical spectroscopy. Efficient routing of energy in ultrathin materials and devices is essential for advancing solar and optoelectronic technologies, and metal–semiconductor nanostructures lie at the center of this effort. Coupling localized surface plasmon in metal with exciton in semiconductor offers a powerful platform for modifying energy landscape and directing energy transport at the nanoscale. This hybridization leads to the formation of exciton–plasmon polaritons, quasiparticles that inherit properties from both light and matter. As a consequence, these coupled states have already been explored for optical switching, nonlinear optics and low threshold nanolasing, underscoring their broad technological relevance. However, experimentally visualizing these coupled states is challenging, requiring advanced optical microscopy and spectroscopic techniques. In my work, we will characterize these hybrid states using spatial modulation spectroscopy and transient absorption microscopy. Spatial modulation spectroscopy will provide spectroscopic signatures of the states by measuring the absolute extinction of individual nanostructures with high sensitivity while transient absorption microscopy will enable time-resolved mapping of exciton–polariton diffusion. Together, these measurements will offer a comprehensive understanding of the formation, dynamics, and transport properties of the coupled states, offering insight into how engineered nanostructures could channel energy more efficiently in solar energy conversion devices.

Current work: Fourier-space optical imaging of exciton–plasmon polaritons (University of Notre Dame, 2024–present)

  • Designed and constructed a custom Fourier-space optical imaging setup to map energy–momentum dispersion curves, enabling the quantification of exciton–plasmon coupling in hybrid nanostructures.
  • Extracted and fitted line profiles from real-space microscopy images to determine polariton propagation lengths.
  • Analyzed group velocity and propagation dynamics to calculate polariton dephasing times, providing insight into the coherence lifetimes of the system.
  • Developed electromagnetic simulations in COMSOL Multiphysics to model energy-transfer pathways and radiation damping, providing a theoretical framework that validated the experimental findings.

Previous research (IISER Pune, India)

Thermal evolution of the structure and luminescence of the hybrid-cation-stabilized [(4AMTP)PbBr2]2PbBr4 layered perovskite (2023–2024)

  • Analyzed low-temperature (8–300 K) SCXRD and PXRD data to evaluate 2D perovskite phase behavior, showing complete phase-transition suppression and enhanced structural rigidity from the hybrid A-site cation.
  • Performed variable-temperature steady-state and time-resolved spectroscopy to map exciton dynamics, uncovering the interplay between bright and dark excitons.
  • Compared the structures of hybrid and conventional 2D perovskites to elucidate the role of the entropy of fusion (ΔSfus) in their thermal behavior, supporting the study Entropy-Driven Reversible Melting and Recrystallization of Layered Hybrid Perovskites.

Te4+/Er3+ co-doped Cs2NaInCl6 double perovskites for short-wave infrared (SWIR) emission (2022–2023)

  • Optimized hydrothermal synthesis parameters for doped double perovskites to fine-tune stoichiometry and maximize SWIR emission efficiency.
  • Characterized samples using PXRD and ICP-MS to determine dopant site incorporation, doping percentages, and lattice distortion, establishing structure–property relationships for host–guest interactions.
  • Conducted temperature-dependent (8–300 K) photoluminescence excitation, emission, and lifetime measurements to elucidate the energy-transfer mechanisms driving SWIR emission.
  • Fabricated a prototype phosphor-converted light-emitting diode (pc-LED) using the optimized phosphors, demonstrating proof-of-concept utility for SWIR optoelectronic devices.