# Nazanin’s article on Si-Ge-Sn alloys published in Phys Rev Applied

Being a good thermoelectric material is a balancing act between high electrical conductivity σ and low thermal conductivity κ, because both quantities depend directly on the flow of electrons. Fortunately, κ also depends on lattice phonons, so this contribution can be cut—for example, by scattering from randomly distributed heavy atoms. The authors’ calculations show that adding tin to alloys of silicon and germanium should yield quite good thermoelectrics, especially in thin-film systems.

Phys. Rev. Applied 6, 014015 (2016) – Published 25 July 2016

# Arnab’s article on length divergence in graphene published in PRB

This article studies how thermal conductivity in graphene ribbons scales with their length and uncovers an unusual logarithmic dependence, while also explaining the eventual convergence beyond 100 um–far longer than the phonon mean free path!

http://dx.doi.org/10.1103/PhysRevB.93.235423

# Ela Correa wins Undergraduate Rising Researcher Award

Gabriela Calinao Correa

The Rising Researcher award is presented to Gabriela Calinao Correa, class of two-thousand-sixteen, for her dedicated pursuit of research with meaningful, tangible, and publishable results. Gabriela’s Honors Thesis led to the development of a new computational model for heat transfer between 2D van der Waals materials (such as graphene) blanketing 3D substrates used in the semiconductor industry to build nanoelectronic devices. She gave a talk on this research at the fall 2015 Materials Research Society Meeting in Boston, Massachusetts, a rare opportunity for an undergraduate researcher. Gabriela’s faculty advisor is Zlatan Aksamija, electrical and computer engineering. Congratulations, Gabriela!

# NVIDIA Academic Hardware Grant Program Awards NTSL 2 Tesla K40 GPU cards

The Nanoelectronics Theory and Simulation Lab is fortunate to have been selected as a recipient of 2 NVIDIA Tesla K40 GPU cards (adding up to a total of 5760 cores, capable of 8.6 Tflops performance!) to accelerate our calculations. This award is part of NVIDIA’s Academic Hardware Grant Program.

http://www.nvidia.com/object/tesla-workstations.html

# Our invention of folded 2-D thermoelectric elements featured on TTO’s website

This invention, co-invented with Prof. Robert Blick of the University of Hamburg, uses folded 2-dimensional materials to reach enhanced thermoelectric conversion efficiencies. 2-D materials like grapheme are great electrical and thermal conductors; by folding them, the thermal path is suppressed, diverting more thermal energy into electrical, thereby increasing thermoelectric conversion efficiency:

http://tto-umass-amherst.technologypublisher.com/tech/Efficient_Thermoelectric_Converters

# Happy leap day B-day to Cameron

NET lab member and MS student Cameron Foss turns 6 years old today.