In collaboration with the Salehi-Khojin group at UIC, we studied the effect of encapsulation on the thermal boundary conductance (TBC) between few-layer MXene (Ti3C2) and the substrate. Cameron’s first-principles simulations explain that encapsulating the MXene with amorphous AlOx nearly doubles the TBC to the substrate because the encapsulation dampens the long-wavelength flexural phonon modes that are responsible for most of the 2D-3D heat transfer. The work has been accepted for publication in the prestigious Advanced Materials (impact factor ~22): https://doi.org/10.1002/adma.201801629
Our recent work on the dynamical thermal conductivity in graphene nanoribbons shows that frequency-dependent thermal transport arises in the hydrodynamic regime. Thermal conductivity resembles a low-pass filter while the normal and resistive components of the heat flux are out of phase with each other. The work is now published in Physical Review B: https://doi.org/10.1103/PhysRevB.98.024303
Our recent work aimed at understanding the heat dissipation, thermal boundary conductance, and Raman spectra in the transition metal dichalcogenide WSe2, done in collaboration with Selehi-Kkhojin’s group at UIC, has been published in ACS Applied Materials and Interfaces. Congratulations Arnab and Cameron, who contributed theory and first-principles simulation of the decay paths of Raman active optical phonons and the thermal boundary conductance between multi-layer WSe2 and the substrate.
Full paper available here: https://dx.doi.org/10.1021/acsami.8b04724
Prof. Zlatan Aksamija was recently quoted in a Science News story about why scientists are studying how 2-D materials such as graphene behave at high temperatures. In the February 13 edition of Science News, Aksamija said that commonly used silicon-based electronics are “hitting a brick wall” regarding how much smaller they can be manufactured, and that 2-D materials could be ideal for constructing the next generation of tiny devices:
Cameron and NETlab alum Ela’s work on the thermal boundary conductance between van der Waals atomic layers and substrates, with impact on device applications on graphene, MoS2 and related materials, was included in Highlights of 2017, section on Energy at the Nanoscale: http://iopscience.iop.org/journal/0957-4484/page/Highlights%202017
Our article will be free to read throughout 2018, offering unlimited access to the work.
Adithya’s recent work on “Thermoelectric Properties of Periodic Quantum Structures in the Wigner-Rode Formalism” has been accepted for publication in a special issue of the Journal of Physics: Condensed Matter. The article is available here: https://doi.org/10.1088/1361-648X/aaa110
The UMass College of Engineering news office has written a nice article about our recent paper on graphene/MoS2 interfaces, published in Scientific Reports. Here is a link to the news article: http://engineering.umass.edu/news/aksamija-and-his-graduate-students-publish-paper-scientific-reports
Prof. Aksamija’s book “Nanophononics: Thermal Generation, Transport, and Conversion at the Nanoscale” now available on Pan Stanford via CRC/Taylor&Francis: https://www.crcpress.com/Nanophononics-Thermal-Generation-Transport-and-Conversion-at-the-Nanoscale/Aksamija/p/book/9789814774413
- The book offers a unique perspective bridging the fields of nanoscale heat transfer and nanoelectronics.
- It covers both fundamentals and applications from the perspectives of theory/simulation, experimental measurements, and device applications.
- It brings together a unique group of leading experts on this topic
Heat in most semiconductor materials, including the traditional group IV elements (Si, Ge, diamond), III–V compounds (GaAs, wide-bandgap GaN), and carbon allotropes (graphene, CNTs), as well as emerging new materials like transition metal dichalcogenides (TMDCs), is stored and transported by lattice vibrations (phonons). Phonon generation through interactions with electrons (in nanoelectronics, power, and nonequilibrium devices) and light (optoelectronics) is the central mechanism of heat dissipation in nanoelectronics.
This book focuses on the area of thermal effects in nanostructures, including the generation, transport, and conversion of heat at the nanoscale level. Phonon transport, including thermal conductivity in nanostructured materials, as well as numerical simulation methods, such as phonon Monte Carlo, Green’s functions, and first principles methods, feature prominently in the book, which comprises four main themes: (i) phonon generation/heat dissipation, (i) nanoscale phonon transport, (iii) applications/devices (including thermoelectrics), and (iv) emerging materials (graphene/2D). The book also covers recent advances in nanophononics—the study of phonons at the nanoscale. Applications of nanophononics focus on thermoelectric (TE) and tandem TE/photovoltaic energy conversion. The applications are augmented by a chapter on heat dissipation and self-heating in nanoelectronic devices. The book concludes with a chapter on thermal transport in nanoscale graphene ribbons, covering recent advances in phonon transport in 2D materials.
The book will be an excellent reference for researchers and graduate students of nanoelectronics, device engineering, nanoscale heat transfer, and thermoelectric energy conversion. The book could also be a basis for a graduate special topics course in the field of nanoscale heat and energy.