Lead-halide perovskite quantum dots (PQDs) are established quantum emitters with potential for entangled photon-pair generation via multiexciton cascades. However, the energetics and dynamics of many-body excitations remain poorly understood. Here, we perform time- and frequency-resolved photon-correlation spectroscopy of single CsPbBr\textsubscript{3} PQDs at low temperatures using a single-photon avalanche diode (SPAD) array detector. We report biexciton binding energies and assign their charged states, which undergo fast (μs) switching dynamics. Most notably, we identify a spectral feature blue-shifted from the exciton by 7.4±1.9 meV as the bound triexciton and establish the order of its cascade emission. These results highlight the power of low-temperature, multidimensional photon-correlation spectroscopy for resolving complex many-body dynamics.
@article{arxiv.2509.12461,
title = {Multi-Dimensional Photon-Correlations Reveal Triexciton Features in Single Perovskite Quantum Dots},
author = {Alex Hinkle and Chieh Tsao and Adam Duell and Hendrik Utzat},
journal= {arXiv preprint arXiv:2509.12461},
year = {2025}
}