Energy Conversion and Heat Transfer

BNC researchers seek to understand and exploit micro- and nanoscale phenomena in active devices and passive components that transfer heat or convert energy from one form to another. These endeavors promise to yield more efficient and higher performance electronics, solar cells utilizing readily available, low toxicity elements without compromising efficiency, thermophotovoltaics, compact and environmentally friendly solid-state refrigeration, safer and higher performance batteries, and solid-state generators that convert a heat flux directly to electric power. Progress in these applications demands an understanding of the coupling between phonons, electrons and photons at length scales comparable to their wavelengths and scattering lengths, and at timescales ranging from femtoseconds to microseconds. BNC is also home to a variety of thermal characterization tools including an ultrafast 800 picosecond thermoreflectance imaging for thermal characterization of active devices with 200-300 nm spatial resolution, sub-picosecond pump-and-probe microscopy system with 10 nm spatial resolution, a diffraction-limited infrared microscope (with 2 µm - 75 µm spatial resolution) for characterizing temperatures in active devices and measuring thermal properties, and several thermoreflectance systems for characterizing thermal conductivity and thermal boundary resistance of thin films.