CAREER: Development and Characterization of New High Thermal Conductivity Materials for Energy-Efficient Electronics and Photonics

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

Non-technical Description: With the ever-shrinking dimensions of electronic and photonic devices to the nanoscale, heat dissipation is an increasingly critical technological challenge. To address this challenge, discovering and understanding the properties of high thermal conductivity materials that can efficiently dissipate heat from hot spots and improve the performance of devices constitute an urgent need. This CAREER project aims to investigate new high thermal conductivity materials and understand the fundamental transport phenomena and mechanisms associated with the chemistry and structures of such materials. The PI is using complementary approaches, including multiscale modeling, advanced synthesis and characterization methods. These less explored materials are theoretically predicted to offer new paradigms to enable advanced electronics, optoelectronics, thermal energy conversion and management. The research components of this project are closely integrated with various education and outreach activities, offering cross-disciplinary training beyond traditional educational boundaries, and involving the participation of underrepresented and diversity groups. This is accomplished through industry-academia collaborations, development of a new interdisciplinary course curriculum, and establishment of a Nano-Energy outreach program. Technical Description: The principal investigator and his research team are investigating a new class of high thermal conductivity materials (such as BAs, BP, GeC) to address the critical challenge of heat dissipation in modern electronics and photonics. Some of these unique materials have been predicted recently by ab initio theory to have ultrahigh thermal conductivity, over 1000 W/mK, enabled by multiple factors, including a large mass ratio of the constitutive atoms, acoustic bunching, and isotopic purity. This CAREER project aims to experimentally realize these high thermal conductivity materials through a synergistic growth-measurement-model approach to investigate the optimum growth conditions, structural and thermal properties, and phonon transport mechanisms. The team develops new characterization tools, including advanced phonon spectral mapping spectroscopy based on the time-domain thermoreflectance technique, and advanced atomic-level material structural control methods, to establish detailed structure-property relationships with microscale quantification. Experimental measurement results including phonon mean free path spectra are analyzed using atomistic density functional theory and multiscale Boltzmann transport equations solved by Monte Carlo simulations. Completion of this project may lead to transformative technological innovations for advancing the performance and energy-efficiency of future electronics and photonics. In addition, the multidisciplinary research components are closely integrated with various education and outreach activities with graduate, undergraduate, and high school students, involving students from underrepresented minority groups. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.