As promising optoelectronic materials, lead sulfide quantum dots (PbS QDs) have attracted great attention. However, their applications are substantially limited by the QD quality and/or complicated synthesis. Herein, a facile new synthesis is developed for highly monodisperse and halide passivated PbS QDs. The new synthesis is based on a heterogeneous system containing a PbCl₂−Pb(OA)₂ solid-liquid precursor solution. The solid PbCl₂ inhibits the diffusion of monomers and maintains a high oversaturation condition for the growth of PbS QDs, resulting in high monodispersities. In addition, the PbCl₂ gives rise to halide passivation on the PbS QDs, showing excellent stability in air. The high monodispersity and good passivation endow these PbS QDs with outstanding optoelectronic properties, demonstrated by a 9.43% power conversion efficiency of PbS QD solar cells with a bandgap of ∼ 0.95 eV (1,300 nm). We believe that this heterogeneous strategy opens up a new avenue optimizing for the synthesis and applications of QDs.

作为有前途的光电材料，硫化铅量子点（PbS QDs）引起了人们的极大关注。然而，它们的应用在很大程度上受到 QD 质量和/或复杂合成的限制。在此，为高度单分散和卤化物钝化的 PbS QD 开发了一种简便的新合成方法。新合成基于包含PbCl ₂ -Pb(OA) ₂固-液前体溶液的多相系统。固体 PbCl ₂抑制单体的扩散并为 PbS QD 的生长维持高过饱和条件，从而导致高单分散性。此外，PbCl ₂引起 PbS QD 上的卤化物钝化，在空气中表现出优异的稳定性。高单分散性和良好的钝化赋予这些 PbS QD 出色的光电特性，带隙为 ∼ 0.95 eV (1,300 nm) 的 PbS QD 太阳能电池的功率转换效率为 9.43%。我们相信，这种异构策略为优化 QD 的合成和应用开辟了一条新途径。