Premium
Intraband Cooling in All‐Inorganic and Hybrid Organic–Inorganic Perovskite Nanocrystals
Author(s) -
Diroll Benjamin T.,
Schaller Richard D.
Publication year - 2019
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201901725
Subject(s) - materials science , nanocrystal , formamidinium , nanocrystalline material , perovskite (structure) , auger effect , excitation , photoluminescence , relaxation (psychology) , exciton , chemical physics , nanotechnology , auger , optoelectronics , atomic physics , condensed matter physics , crystallography , chemistry , psychology , social psychology , physics , engineering , electrical engineering
Intraband relaxation in all‐inorganic cesium lead tribromide (CsPbBr 3 ) and hybrid organic–inorganic formamidinium lead tribromide (FAPbBr 3 ) nanocrystals is experimentally investigated for a range of particle sizes, excitation energies, sample temperatures, and excitation fluences. Hot carriers in CsPbBr 3 nanocrystals consistently exhibit slower cooling than FAPbBr 3 nanocrystals in the single electron–hole pair per nanocrystal regime. In both compositions, long‐lived hot carriers (>3 ps) are only observed at excitation densities corresponding to production of multiple electron–hole pairs per nanocrystal—and concomitant Auger recombination. These presented results are distinct from previous reports in bulk hybrid perovskite materials that convey persistent hot carriers at low excitation fluences. Time‐resolved photoluminescence confirms the rapid cooling of carriers in the low‐fluence (single electron–hole pair per nanocrystal) regime. Intraband relaxation processes, as a function of excitation energy, size, and temperature are broadly consistent with other nanocrystalline semiconductor materials.