Despite recent advances, the synthesis of colloidal InSb quantum dots (QDs) remains underdeveloped, mostly due to the lack of suitable precursors. In this work, we use Lewis acid–base interactions between Sb(III) and In(III) species formed at room temperature in situ from commercially available compounds (viz., InCl₃, Sb[NMe₂]₃ and a primary alkylamine) to obtain InSb adduct complexes. These complexes are successfully used as precursors for the synthesis of colloidal InSb QDs ranging from 2.8 to 18.2 nm in diameter by fast coreduction at sufficiently high temperatures (≥230 °C). Our findings allow us to propose a formation mechanism for the QDs synthesized in our work, which is based on a nonclassical nucleation event, followed by aggregative growth. This yields ensembles with multimodal size distributions, which can be fractionated in subensembles with relatively narrow polydispersity by postsynthetic size fractionation. InSb QDs with diameters below 7.0 nm have the zinc blende crystal structure, while ensembles of larger QDs (≥10 nm) consist of a mixture of wurtzite and zinc blende QDs. The QDs exhibit photoluminescence with small Stokes shifts and short radiative lifetimes, implying that the emission is due to band-edge recombination and that the direct nature of the bandgap of bulk InSb is preserved in InSb QDs. Finally, we constructed a sizing curve correlating the peak position of the lowest energy absorption transition with the QD diameters, which shows that the band gap of colloidal InSb QDs increases with size reduction following a 1/d dependence.

中文翻译：

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从原位生成的单源前体发光胶体InSb量子点。

尽管有最新进展，但胶体InSb量子点（QDs）的合成仍不发达，主要是由于缺乏合适的前体。在这项工作中，我们使用室温下由市售化合物（即InCl ₃，Sb [NMe ₂ ] _3）原位形成的Sb（III）和In（III）物种之间的路易斯酸碱相互作用和伯烷基胺）来获得InSb加合物。这些配合物通过在足够高的温度（≥230°C）下快速共感应成功地用作合成胶体InSb QD的前体，其直径范围为2.8至18.2 nm。我们的发现使我们能够为我们的工作中合成的量子点提出形成机制，该机制基于非经典的成核事件，然后是总体增长。这产生具有多峰尺寸分布的合奏，其可以通过合成后的尺寸分馏以具有相对窄的多分散性的子合分馏。直径低于7.0 nm的InSb QD具有锌混合晶体结构，而较大QD（≥10nm）的整体由纤锌矿和锌混合QD的混合物组成。这些量子点表现出的光致发光具有较小的斯托克斯位移和短的辐射寿命，这意味着发射是由于带边重组，并且InSb量子点中保留了块状InSb的带隙的直接性质。最后，我们建立了一条尺寸曲线，将最​​低能量吸收跃迁的峰位置与QD直径相关联，这表明胶态InSb QD的带隙随着尺寸的减小而随1 /d依赖。