Latest News

 

Building a Sunnier Energy Future

Published on September 3, 2019 by Aaron Dubrow



Solar photovoltaics have shown great potential in the past few decades as a major contributor towards achieving a carbon-free planet. In addition to today's silicon-based solar materials, researchers are exploring organic polymer materials, which have shown promise due to their remarkable ability to transform light into energy at a lower cost.

A cover figure from the July issue of the Journal of Polymer Science, based on research from Balasubramanian's group.

Ganesh Balasubramanian, an assistant professor of Mechanical Engineering and Mechanics at Lehigh University, was among the early users of Frontera — the fastest academic supercomputer in the world — studying the dynamics of organic photovoltaic materials. Actively collaborating with experimentalists, he is working to develop efficient ways to create next generation flexible solar photovoltaics that can exceed the energy-producing potential of today's devices.

Using simulations, Balasubramanian tries to replicate an actual experiment by virtually mimicking a particular physical system. Doing so allows him to understand the forces at play on an atomic level.

"Our work involves simulation of solvent evaporation processes found in a typical spin coating experiment," Balasubramanian said. "In order to compare results from atomistic simulations with images produced during experiments, large-scale computations are required."

His typical simulations contain over one hundred million superatoms (a cluster of atoms that exhibit some of the properties of elemental atoms), and replicate the physical movements and interactions among these superatoms.

"Understanding the morphology of these large-scale simulations would help us correlate the structure, properties, and performance of organic photovoltaics," he said.

Alongside these large simulations, Balasubramanian also performs computations to optimize the design variables in order to improve specific properties. "These require enormous computing efforts across several compute nodes, and supercomputing system like Frontera are the best choice for this purpose," he said.

(Left to Right) Joydeep Munshi, Ganesh Balasubramanian and Ankit Roy.

Balasubramanian previously used compute clusters at his university, as well as those hosted by the Department of Defense through their High Performance Computing Modernization Program.

"We hope to harness Frontera's ultrafast computational capabilities to accelerate our search for better organic photovoltaics," he said. "With some of our initial simulations on Frontera, we have been able to improve by a factor of four to five, in terms of computing speed."

Whereas a simulation of 100,000 atoms and few million timesteps would be carried out at the rate of 100 timesteps per second on a normal supercomputer, on Frontera, Balasubramanian has achieved speeds of approximately 500 timesteps per second.

Balasubramanian's students visited TACC in the spring and met with Kent Milfeld from TACC's High Performance Computing team in anticipation of using Frontera.

"We hope to harness Frontera's ultrafast computational capabilities to accelerate our search for better organic photovoltaics. With some of our initial simulations on Frontera, we have been able to improve by a factor of four to five, in terms of computing speed."
Ganesh Balasubramanian, Lehigh University

"This trip proved to be very beneficial for us and helped us better understand the functioning of the supercomputer and ways to harness the best computational performance," said Joydeep Munshi, a graduate research assistant in Balasubramanian's lab.

"We learned about available MPI stacks and how to tune MPI and hybrid — MPI+OpenMP — applications via environment variables," Munshi said. "We were also informed about several applications such as Lammps, Gromacs, and VASP, which are relevant to our research and will be available on Frontera nodes."

Using the fastest academic supercomputer in the world fills Balasubramanian with a sense of privilege as a researcher. "The lightning speed at which Frontera performs computations is very beneficial in terms of saving time," he said. "Overall, the entire pace of computational research will be increased by the arrival of Frontera."


This research is supported by the NSF Division Of Civil, Mechanical, & Manufacturing Innovation, within the NSF Directorate for Engineering: Award #1753770: Collaborative Research: Concurrent Design of Quasi-Random Nanostructured Material Systems (NMS) and Nanofabrication Processes using Spectral Density Function


Contact

Faith Singer-Villalobos

Communications Manager
faith@tacc.utexas.edu | 512-232-5771

Aaron Dubrow

Science And Technology Writer
aarondubrow@tacc.utexas.edu

Jorge Salazar

Technical Writer/Editor
jorge@tacc.utexas.edu | 512-475-9411