Extended Data Fig. 4: Atomistic insight into electronic wavefunction delocalization in core/shell CsPbBr3/CsCaBr3 quantum dots via ab initio molecular dynamics at the DFT level of theory.
From: Single-photon superradiance in individual caesium lead halide quantum dots
a, The LUMO density localizes on the surface (edges and corners) in models without surface passivation. b, Cross-section of a core/shell CsPbBr3/CsCaBr3 model revealing the 2.4 nm CsPbBr3 core with a single layer of CsCaPb3 shell. c, LUMO (left) and HOMO (right) wavefunctions of the core/shell model. Both states are fully delocalized across the core due to electronic passivation by the shell. d, Representative snapshot of the LUMO density at 3 K (left) and 150 K (right) projected onto the y-z plane. e, Time-averaged inverse participation ratio (IPR; degree of localization) of the LUMO density at 3 and 150 K, revealing thermally induced localization. Error bars indicate 95% confidence intervals. f, Time-averaged root-mean-squared displacement (RMSD) of the LUMO density center from the QD center at 3 and 150 K, showing thermally induced dynamic spatial fluctuations. Error bars indicate 95% confidence intervals. g–i, Phonon-induced LUMO dephasing in CsPbBr3 QDs: the dephasing function D(t) related to the LUMO at (g) 3 K and (h) 150 K, respectively, is obtained from the temporal fluctuations of the LUMO energy (see insets). i, The extracted pure-dephasing time τ2* strongly decreases with increasing temperature. j–l, Phonon-induced band gap dephasing in CsPbBr3 QDs, analyzed analogously to the LUMO results in (g)-(i).
