Up-converted photoluminescence from C H3 N H3Pb I3 perovskite semiconductors: Implications for laser cooling

Abstract

Up-converted photoluminescence (PL), or, in other words, anti-Stokes PL via phonon absorption in semiconductors is a critical property for realizing optical refrigeration. Here, we investigate the anti-Stokes PL from optically thin films and thick crystals of CH3NH3PbI3 to assess their potential for laser cooling. Using PL excitation spectroscopy, we determine the excitation photon energy that maximizes the cooling efficiency. The evaluated up-conversion gain for the thick single crystal is close to 70% of that for the thin film, indicating a possibility for laser cooling even in thick crystals. We discuss the competition between anti-Stokes PL and photon reabsorption in CH3NH3PbI3.