Leveraging novel nanothermometries and first-principles-based computational frameworks to uncover disruptive energy transfer mechanisms in nanostructures
Abstract
The comprehensive understanding and control of nanoscale thermal transport processes involving many-body interactions of the fundamental energy carriers (namely, electrons, phonons and photons) in solid materials underpins the advancements in a plethora of technologies. For instance, the rapid miniaturization and faster working speeds of microelectronic devices causes local hot spots due to the preferential excitation of some energy carriers (such as electrons) resulting from large external fields in the devices. Mitigating these hot spots through efficient thermal management strategies is crucial for the further enhancement of the device efficiencies. However, our current understanding of these many-body interactions involving the energy carriers has been limited to "near-equilibrium" conditions mainly due to limitations imposed by the lack of experimental techniques that are able to simultaneously access ultrafast time regimes (picoseconds to nanoseconds) and nanometric length scales that are typically associated with the fundamental energy carrier scattering events. Therefore, the overarching objective of this proposal is leveraging novel ultrafast thermometry techniques with nanometric spatial resolutions along with developing cutting-edge atomistic computational frameworks to fully understand these many-body interactions and control these processes through nanostructuring and application of external fields. This will ultimately lead to the realization of programmable energy transport properties in novel material systems crucial for advancing the next-generation of microelectronics that are critical to the Navy.Specifically, we will develop a novel ultrafast pump-probe metrology with spatial resolution in the order of 20 nm and access energy transport for conditions of high carrier densities as well as high temperature perturbations in novel semiconductors. We will support these experiments with fully first-principles based calculations of electron-phonon coupling at elevated electron temperatures and molecular dynamics simulations based on machine learning interatomic potentials capable of capturing all the higher-order vibrational interactions to comprehensively understand the mode-resolved properties. Through these efforts, our proposed program will go beyond the conventional approach of studying the energy carrier "scattering" picture in the small temperature perturbation regime and assess (and control) nanoscale energy transport for far-from-equilibrium conditions at elevated and device relevant temperatures. We will apply our newly developed techniques to understand interfacial heatflow in wide band gap semiconductors that are ubiquitous in microelectronic devices. We will also implement the new techniques to unravel various energy conversion mechanism in covalent organic frameworks that have the potential to revolutionize how we generate, store, and use energy. As such, the expected outcomes of the proposed project will not only be transformative for our basic scientific understanding of energy carrier dynamics but will also be disruptive for the future development of next generation devices for various types of energy-related applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 08, 2024
- Source ID
- N000142412419
Entities
People
- Ashutosh Giri
Organizations
- Office of Naval Research
- United States Navy
- University of Rhode Island