Spontaneous crystallization of strongly confined CsSn<sub>x</sub>Pb<sub>1-x</sub>I<sub>3</sub> perovskite colloidal quantum dots at room temperature.

Zhang, Louwen; Zhou, Hai; Chen, Yibo; Zheng, Zhimiao; Huang, Lishuai; Wang, Chen; Dong, Kailian; Hu, Zhongqiang et al. · Nat Commun · 2024

basic_science · Level V

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Abstract

The scalable and low-cost room temperature (RT) synthesis for pure-iodine all-inorganic perovskite colloidal quantum dots (QDs) is a challenge due to the phase transition induced by thermal unequilibrium. Here, we introduce a direct RT strongly confined spontaneous crystallization strategy in a Cs-deficient reaction system without polar solvents for synthesizing stable pure-iodine all-inorganic tin-lead (Sn-Pb) alloyed perovskite colloidal QDs, which exhibit bright yellow luminescence. By tuning the ratio of Cs/Pb precursors, the size confinement effect and optical band gap of the resultant CsSn<sub>x</sub>Pb<sub>1-x</sub>I<sub>3</sub> perovskite QDs can be well controlled. This strongly confined RT approach is universal for wider bandgap bromine- and chlorine-based all-inorganic and iodine-based hybrid perovskite QDs. The alloyed CsSn<sub>0.09</sub>Pb<sub>0.91</sub>I<sub>3</sub> QDs show superior yellow emission properties with prolonged carrier lifetime and significantly increased colloidal stability compared to the pristine CsPbI<sub>3</sub> QDs, which is enabled by strong size confinement, Sn<sup>2+</sup> passivation and enhanced formation energy. These findings provide a RT size-stabilized synthesis pathway to achieve high-performance pure-iodine all-inorganic Sn-Pb mixed perovskite colloidal QDs for optoelectronic applications.