Optically Cooling Cesium Lead Tribromide Nanocrystals Academic Article uri icon


  • One photon up-conversion photoluminescence is an optical phenomenon whereby the thermal energy of a fluorescent material increases the energy of an emitted photon compared with the energy of the photon that was absorbed. When this occurs with near unity efficiency, the emitting material undergoes a net decrease in temperature, so-called optical cooling. Because the up-conversion mechanism is thermally activated, the yield of up-converted photoluminescence is also a reporter of the temperature of the emitter. Taking advantage of this optical signature, cesium lead trihalide nanocrystals are shown to cool during the up-conversion of 532 nm CW laser excitation. Raman thermometric analysis of a substrate on which the nanocrystals were deposited further verifies the decrease in the local environmental temperature by as much as 25 °C during optical pumping. This is the first demonstration of optical cooling driven by colloidal semiconductor nanocrystal up-conversion.

author list (cited authors)

  • Roman, B. J., Villegas, N. M., Lytle, K., & Sheldon, M.

complete list of authors

  • Roman, Benjamin J||Villegas, Noel Mireles||Lytle, Kylie||Sheldon, Matthew

publication date

  • January 1, 2020 11:11 AM