The final PhD Defence of Mr. Amey G Gokhale, is scheduled for Monday, June 30, from 3:00 PM to 4:00 PM in the ME Auditorium, Mechanical Engineering Department. 

Title:  Thermal Transport in Layered Materials
Date & Time: June 30, 3:00–4:00 PM 
Venue: ME Auditorium, Department of Mechanical Engineering 

Examination Committee: 

External Examiner: Prof. Biswarup Pathak, Department of Chemistry, IIT Indore. 

Chairperson: Prof. Alok Shukla, Department of Physics, IIT Bombay. 

Internal Examiner: Prof. Amit Singh, Mechanical Engineering Department, IIT Bombay. 

Supervisor: Prof. Ankit Jain, Mechanical Engineering Department, IIT Bombay. 

Abstract: 
Understanding phonon-mediated thermal transport in nano-structured layered semiconductors is critical for applications ranging from electronic thermal management to thermoelectric energy conversion. In these materials, heat is primarily carried by phonons, and accurate prediction of thermal conductivity requires detailed analysis of phonon mode-level transport. This work employs density functional theory (DFT) to compute harmonic and anharmonic force constants, explicitly accounting for interlayer van der Waals (vdW) interactions. These force constants are then used to solve the Boltzmann Transport Equation (BTE), incorporating phonon-phonon, phonon-defect, and boundary scattering mechanisms for realistic thermal conductivity predictions. We investigated thermal transport in a broad set of layered materials with thermal conductivities spanning two orders of magnitude. We distinguish the transport regimes in high (e.g., AlB₆, MoS₂, MoSi₂N₄) and low (e.g., MoO₃, KCuSe) conductivity materials. For high-conductivity materials, cross-plane transport is dominated by long mean free path acoustic phonons, making it highly thickness-sensitive, while in low-conductivity systems, phonons exhibit comparable mean free paths in both directions. Furthermore, to reduce computational cost, we develop a non-uniform Brillouin zone sampling approach within the BTE framework. This method selectively samples phonon modes based on their contributions to scattering processes, achieving a 10× reduction in computational effort while maintaining thermal conductivity prediction accuracy within 10% of the conventional uniform sampling approach. This enables efficient and accurate modeling of thermal transport in layered systems.

About the Candidate: 

Amey is a Ph.D. researcher in the Mechanical Engineering department at IIT Bombay, working towards understanding and optimizing thermal transport in semiconductors. His current research focuses on the cross-plane thermal transport in layered materials using first-principles methods, and on accelerating Boltzmann Transport Equation (BTE) calculations for such materials. He has completed his undergraduate studies in Mechanical Engineering from the University of Mumbai, Maharashtra, and later pursued M.Tech. in Thermal Science and Engineering from IIT Bhubaneswar, where he worked on predicting supersonic flow field using computational fluid dynamics (CFD). Beyond academics, Amey is actively involved in sports at the institute level. He has represented the Mechanical Engineering Department in chess tournaments. Known for his optimism and kind-hearted nature, he maintains a friendly and approachable demeanor both inside and outside the lab.