Carrier Dynamics of Strongly Confined CsPbI<sub>3</sub> Nanowires.

Oddo, Alexander M; Cho, Hanguk; Rana, Rohit; Chabeda, Daniel; Jiang, Yuxin; Verbitsky, Lior; Song, Chengyu; Rabani, Eran et al. · ACS Nano · 2026

basic_science · Level V

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Abstract

We investigate the carrier dynamics of strongly confined cesium lead iodide (CsPbI<sub>3</sub>) nanowires and compare them with weakly confined quantum dots (QDs) to understand how dimensionality affects recombination processes. Using time-resolved photoluminescence and ultrafast transient absorption spectroscopy, we find that nanowires exhibit a 5× faster recombination rate and more rapid carrier cooling than QDs. These differences are attributed to enhanced carrier interactions with trap states. Although nanowires exhibit slightly enhanced radiative rates as a result of confinement, their photoluminescence quantum yield remains relatively low, 23 ± 8%, due to competition from nonradiative recombination processes that occur at a faster rate. These findings highlight a dimensionality-dependent trade-off between radiative efficiency and nonradiative losses, providing insight into the limitations and opportunities for low-dimensional perovskite nanostructures. Our results establish design principles for tailoring CsPbI<sub>3</sub> nanocrystal dimensionality to optimize optical performance in optoelectronic applications such as LEDs and solar cells.