Our mission: 

The non-renewables required for electricity generations, involved transport and manufacturing processes reject large amounts of energy as low-grade waste heat. More precisely, according to the national energy consumption report, more than 60% of the current energy usages are typically rejected as thermal energy, which necessitates the thermal energy engineering without entailed substantial cost.  

In a narrower context, the outperformance of high-end industrial applications can be achieved by the transformation of the energy transfer properties, which are ultimately determined by microscopic transport properties of the energy-carrying quasi-particles such as phonons, electrons, polarons, excitons and polaritons. 

By employing optical spectroscopy and ultrafast electron microscopy, we systematically investigate transport phenomena of microscopic energy (thermal and electronic) carriers, to develop highly efficient novel energy materials and devices. Specifically, we seek to study thermal conduction in inorganic / organic materials, radiative cooling, and ultrafast photocarrier imaging.

[1] H. Kim†, H. Kim†, and T. Kim, "A perspective on inelastic light scattering spectroscopy for probing transport of collective acoustic excitations", Applied Physics Letters, 127, 24, 240501 (Dec. 2025)

[2] S. Kim and T. Kim, "High thermal conductivity dominated by thermal phonons with mean free paths exceeding hundred nanometer in three-dimensional covalent organic framework derivatives: a molecular dynamics study", Journal of Physical Chemistry C, 129, 32, 14614-14621 (May. 2025)

[3] H. Kim and T. Kim, In preparation

[4] H. Kim and T. Kim, In preparation

[5] T. W. Yoo, M. H. Cho, T. Kim, H. Y. Chung, Y. S. Lee*, S. H. Yang*, "A coarse-grained modeling scheme to characterize thermal transport properties in thermoplastic polymers ", International Communications in Heat and Mass Transfer, 158, 107908 (Nov. 2024)

[3] T. Kim, S. X. Drakopoulos, S. Ronca, A. J. Minnich, “Origin of high thermal conductivity in disentangled ultra-high molecular weight polyethylene films: ballistic phonons within enlarged crystals”, Nature Communications, 13(1), 2452, (2022)

[4] T. Kim., J. Moon, A. J. Minnich, "Origin of micron-scale propagation lengths of heat-carrying acoustic excitations in amorphous silicon", Physical Review Materials 5, 065602, (Jun. 2021).

[1] S. H. Cho, Y. Jung, Y.-W. Jang, H. Kim, J. Kim, C. Lim, K.-T. Park. S. Kim, Y. H. Chu, T. Kim, J. Lee, C. Lee, J. Park, K. T. Yoon, D. Eom, S. Park, T. Kim, Y. S. Lee, "Fabrication strategies for 2D halide perovskite towards next-generation optoelectronic applications", International Journal of Precision Engineering and Manufacturing-Green Technology (Jan. 2025)

[2] T. Kim, S. Park, V. Iyer, B. Shaheen, U. Choudhry, Q. Jiang, G. Eichman, R. Gnabasik, K. Kelley, B. Lawrie, K. Zhu, B. L. Liao, “Mapping the pathways of photo-induced ion migration in organic-inorganic hybrid halide perovskites”, Nature Communications, 14, 1846 (Apr. 2023)

[3] U. Choudhry, F. Pan, X. He, B. Shaheen, T. Kim, R. Gnabasik, G. A. Gamage, H. Sun, A. Ackerman, D.-S. Yang, Z. Ren, B. L. Liao, “Persistent hot carrier diffusion in boron arsenide single crystals imaged by ultrafast electron microscopy”, Matter, 6, 206 (Jan. 2023) 

[4] T. Kim, S. Oh, U. Choudhry, C. Meinhart, M. L. Chabinyc, B. Liao, “Transient strain induced electronic structure modulation in a conducting polymer imaged by scanning ultrafast electron microscopy”, Nano Letters, 21, 9146, (Oct. 2021) 

[1] H. Oh and T. Kim, "Thermal transport and the impact of hydrogen adsorption in Linde type A zeolitic imidazolate frameworks", Journal of Physical Chemistry C, 129, 41, 18799-18805 (Oct. 2025)