Observation of Ultrafast Exciton–Exciton Annihilation in CsPbBr₃ Quantum Dots

Excited-state dynamics of CsPbBr3 quantum dots (QDs) are studied through femtosecond transient absorption spectroscopy measurements. The band-edge recombination is dominated by a single exciton process at low excitation density (<0.1 exciton QD−1). While a density-dependent quadratic decay is found in early probe decay at high excitation density (>0.25 exciton QD−1), which is attributed to exciton–exciton annihilation. Moreover, ultrafast biexcitons and slow trap-state excitons are also found with resonant energy slightly below the band edge. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.