As a cost-effective batch synthesis method, Si quantum dots (QDs) with near-infrared photoluminescence, high quantum yield (>50% in polymer nanocomposite), and near-unity internal quantum efficiency were fabricated from an inexpensive commercial precursor (triethoxysilane, TES), using optimized annealing and etching processes. The optical properties of such QDs are similar to those prepared from state-of-the-art precursors (hydrogen silsesquioxane, HSQ) yet featuring an order of magnitude lower cost. To understand the effect of synthesis parameters on QD optical properties, we conducted a thorough comparison study between common solid precursors: TES, HSQ, and silicon monoxide (SiO), including chemical, structural, and optical characterizations. We found that the structural nonuniformity and abundance of oxide inherent to SiO limited the resultant QD performance, while for TES-derived QDs this drawback can be avoided. The presented low-cost synthetic approach would significantly favor applications requiring high loading of good-quality Si QDs, such as light conversion for photovoltaics.

中文翻译：

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具有接近统一的内部量子效率的硅量子点的低成本合成

作为一种经济高效的批量合成方法，具有近红外光致发光、高量子产率（在聚合物纳米复合材料中>50%）和接近统一的内量子效率的 Si 量子点（QD）是由廉价的商业前体（三乙氧基硅烷， TES)，使用优化的退火和蚀刻工艺。这种量子点的光学特性类似于由最先进的前体（氢倍半硅氧烷，HSQ）制备的量子点，但成本却低了一个数量级。为了了解合成参数对 QD 光学特性的影响，我们对常见的固体前体进行了彻底的比较研究：TES、HSQ 和一氧化硅 (SiO)，包括化学、结构和光学表征。我们发现 SiO 固有的结构不均匀性和丰富的氧化物限制了所得的 QD 性能，而对于 TES 衍生的 QD，可以避免这种缺点。所提出的低成本合成方法将显着有利于需要高负载高质量 Si QD 的应用，例如光伏的光转换。