As potential low-cost alternatives of traditional bulk HgCdTe crystals, HgTe colloidal quantum dots (CQDs) synthesized through reactions between HgCl₂ and trioctylphosphine-telluride in hot oleylamine have shown promising performances in mid-wave infrared photodetectors. Tetrapodic or tetrahedral HgTe CQDs have been obtained by tuning the reaction conditions such as temperature, reaction time, concentrations, and ratios of the two precursors. However, the principles governing the growth dynamics and the mechanism behind the transitions between tetrapodic and tetrahedral HgTe CQDs have not been sufficiently understood. In this work, synthesis of HgTe CQDs through bilateral injection is introduced to study the growth mechanism. It suggests that tetrahedral HgTe CQDs usually result from the breaks of tetrapodic HgTe CQDs after their legs grow thick enough. The fundamental factor determining whether the growth makes their legs longer or thicker is the effective concentration of the Te precursor during the growth, rather than temperature, Hg-rich environment, or reactivity of precursors. A chemical model is proposed to illustrate the principles governing the growth dynamics, which provides valuable guidelines for tuning the material properties of HgTe CQDs according to the needs of applications.

中文翻译：

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通过双边注射了解 HgTe 胶体量子点的生长机制

作为传统块状 HgCdTe 晶体的潜在低成本替代品，通过 HgCl ₂和三辛基碲化膦在热油胺中反应合成的 HgTe 胶体量子点（CQD）在中波红外光电探测器中表现出了良好的性能。通过调节温度、反应时间、浓度和两种前驱体的比例等反应条件，可以获得四足或四面体 HgTe CQD。然而，控制生长动力学的原理以及四面体和四面体 HgTe CQD 之间转变的机制尚未得到充分理解。在这项工作中，引入了通过双边注入合成 HgTe CQD 来研究其生长机制。这表明四面体 HgTe CQD 通常是由于四足 HgTe CQD 的腿长得足够厚后断裂而产生的。决定生长是否使它们的腿更长或更粗的根本因素是生长过程中Te前体的有效浓度，而不是温度、富汞环境或前体的反应性。提出了一个化学模型来说明控制生长动力学的原理，这为根据应用需求调整 HgTe CQD 的材料性能提供了有价值的指导。