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arXiv · 2411.09526

Binding energy of polaronic trions and biexcitons in CsPbBr$_3$ nanocrystals

Jose L. Movilla·Josep Planelles·Juan I. Climente
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Abstract

The effect of polaron formation on the ground state of excitons, trions and biexcitons confined in CsPbBr$_3$ nanocrystals is studied in the framework of effective mass Hamiltonians, using a Haken-like (Bajaj) potential for carrier-phonon coupling. The binding energy of trions agrees well with that observed in experiments, with position-dependent dielectric screening playing a significant role. For biexcitons, however, neither polaronic effects, nor dielectric confinement, nor electronic correlations -- here accounted for with a variational Quantum Monte Carlo method -- suffice to explain the large binding energies reported by single nanocrystal spectroscopy experiments. This result reinforces the hypothesis that biexcitons polarize the perovskite lattice differently from excitons and trions.

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Jose L. Movilla, Josep Planelles, Juan I. Climente. 2024-11-14. Binding energy of polaronic trions and biexcitons in CsPbBr$_3$ nanocrystals. https://doi.org/10.1103/physrevb.111.155304

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