Research Areas

  • Energy Conversion (Photovoltaics and Thermoelectrics)
    Dr. Kuntal Roy

    The role of energy is very noteworthy - both the need to supply electrical energy to devices and the need to manage the dissipated energy in a chip. While the information-processing equipments consume a significant fraction of the total electricity production, the hotspots on a chip due to excessive energy dissipation causing system failure has posed a severe challenge to the continuing growth of electronics. While photovoltaic devices have promise to tackle the first issue, the dissipated heat on chips can be taken away by on-chip thermoelectric devices.

    The 3rd generation solar cells exploiting the size quantization effects (e.g., phonon-bottleneck effects, multiple-excitation generation from a single photon) of low-dimensional structures (e.g., quantum wells, wires, dots) have shown promise of being simultaneously high-efficiency and low-cost. Also, with the advent of low-dimensional nanostructures, there have been a surge of radical efforts in constructing highly-efficient thermoelectric devices (the figure of merit, ZT > 3). Deeper understandings of charge and heat transport in nanostructures are the fundamental scientific challenges, which could facilitate in predicting materials for building thermoelectric devices suitable for our needs.

    The spin-based counterparts for the energy conversion devices (e.g., using phot-spin-voltaic effect, spin Seebeck effect) are fundamentally intriguing and promising for technological applications too.