Exploring Zintl-Phase Quantum Dots for Optoelectronic Applications

Growing semiconductors as colloidal quantum dots (QDs) can enable enhanced functionality and processability in a materials system for optoelectronic applications. Recently, semiconducting Zintl-phase BaCd₂P₂ was identified through computational and empirical studies as an excellent candidate for solar energy harvesting.¹ Inspired by the suggested defect tolerance and desirable bandgap, we have developed the growth of BaCd₂P₂ QDs via hot injection. The band gap in BaCd₂P₂ QDs is tunable from ~1.45 eV to 1.8 eV by size control with particles ranging from 3 nm to 9 nm in size. XRD, Raman, and selected area electron diffraction suggest these QDs exist in the P-3m1 space group which matches the bulk. Time resolved photoluminescence measurements were used to determine the photoexcited carrier lifetime is 100 ns. In addition, we demonstrate super lattice formation as well as a cation exchange reaction in these QDs. These results inspire integration of these BaCd₂P₂ QDs into optoelectronic devices and any new developments will be presented. As the Zintl-phase materials space is underexplored for semiconductors and specifically QDs, this initial demonstration and synthetic framework opens up possibilities in these exciting new QD materials.
Reference
(1) Yuan, Z.; Dahliah, D.; Hasan, M. R.; Kassa, G.; Pike, A.; Quadir, S.; Claes, R.; Chandler, C.; Xiong, Y.; Kyveryga, V.; Yox, P.; Rignanese, G.-M.; Dabo, I.; Zakutayev, A.; Fenning, D. P.; Reid, O. G.; Bauers, S.; Liu, J.; Kovnir, K.; Hautier, G. Discovery of the Zintl-Phosphide BaCd2P2 as a Long Carrier Lifetime and Stable Solar Absorber. Joule 2024, 8 (5), 1412–1429. https://doi.org/10.1016/j.joule.2024.02.017.