Rising Stars 2020:

Meenakshi Upadhyaya

PhD Candidate

University of Massachusetts Amherst

Areas of Interest

  • Energy
  • Physical Electronics
  • Scientific Computing
  • Computational Material Science


Organic Thermoelectrics: Transforming Waste Heat into Clean Energy


Organic semiconductors offer advantages such as low cost due to inexpensive fabrication methods and large area production, thus hold tremendous potential to address the demand for cheap and sustainable thermoelectric (TE) materials. Modelling TE materials with high efficiency is a multifaceted problem due to the correlation between material properties, as improving one almost always adversely affects the other. High TE efficiency requires a high electrical conductivity and Seebeck coefficient and a low thermal conductivity. Polymers have an inherently low thermal conductivity, however, they need to be electrochemically doped to improve their electrical conductivity which introduces complexities in the electronic structure because of poor screening of dopant-polymer interactions.

I study the effect of morphology, dopant-polymer Coulombic interactions and charge transport dynamics on both the electronic density-of-states and the Seebeck vs. electrical conductivity trends. Our charge transport model is based on electron hopping between localized sites in the polymer and a modified Gaussian disorder model to account for the impact of doping. We iteratively solve the non-linear Pauli’s master equation to compute time-averaged occupational probabilities of the sites from which relevant transport quantities are calculated. Our results highlight the importance of tuning the Seebeck vs. electrical conductivity trends using the spatial distribution of dopants and dopant-carrier Coulomb interactions to obtain the highest efficiency for TE applications.


I am a PhD candidate in the NanoEnergy and Thermophysics Lab at University of Massachusetts Amherst, advised by Prof. Zlatan Aksamija. My research interests include the study of electrical and thermal transport, and nanoengineering techniques to identify novel semiconductor materials for thermoelectric devices that can efficiently harvest waste heat. I received my Bachelors in Electronics and Communication Engineering from BNM Institute of Technology, India and Masters in Nanotechnology from Vellore Institute of Technology, India. Prior to my PhD, I was a research assistant at the Jawaharlal Nehru Centre for Advanced Scientific Research, India working on computational organic photovoltaics.

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