Automatized colloidal particle synthesis for knowledge-based product design

本项目的目的是建立一个研究平台，用于快速采样的高重复性，自动化合成量子限制半导体纳米颗粒（量子点，QD）。选择量子点是因为它们新颖且增强的尺寸依赖性光电特性，这使它们成为电子器件和可再生能源新兴领域的理想候选者。然而，最小量子点的受控合成遵循复杂的协议，需要经验丰富的实验人员。获得复杂的结构-性能关系，其中粒度分布（PSD）的最小偏差、周围无机壳的存在和组成的偏差，甚至表面化学的偏差对产品性能产生最大影响（吸光度和发射）。通过自动化和快速取样，应包括以下几点：i）将复杂的实验室方案转移到自动化的工作流程，ii）在要求苛刻的合成条件下最大程度地排除人为因素以获得上级再现性，iii）建立重要的工艺-结构-性质关系，iv）快速有效地筛选用于材料开发的大参数空间，以及v）提取动力学参数以用于颗粒形成的机械理解。解决这些问题是必要的，以便明确了解从小构件到功能器件质量的工艺链中的哪些步骤丢失了，以及如何设计和加工新材料以获得最佳产品特性。第二个资助期的工作重点是发展粒子形成过程（包括成核、生长和成熟）的机械研究程序。在这种情况下，一个合理的高通量（HT）的纯化和分类方面的后处理也需要开发。因此，HT颗粒合成将被确立为确定最佳合成方案的高度可靠的方法。在第一个资助期内，应遵循以下方向：首先，应开发HT合成和HT表征方案，以及PSD方面的分散性和量子产率（QY）方面的产品性能。同时，将建立颗粒形成早期阶段（< 10 s）的可重现采样。然后，应详细研究加热和冷却曲线以及特征混合时间方面的系统特性。后者对于第一个供资期的最后一部分至关重要，在这一部分，将有效地筛选大参数空间，并建立重要的工艺-结构以及结构-性能函数。

Aim of this project is to establish a research platform for highly reproducible, automatized synthesis of quantum confined semiconductor nanoparticles (quantum dots, QDs) with fast sampling. QDs were chosen due to their novel and enhanced size-dependent opto-electronic properties which make them ideal candidates in the emerging fields of electronic devices and renewable energy. However, the controlled synthesis of smallest QDs follows elaborate protocols that require highly experienced experimentalists. Complex structure-property relationships are obtained where minimal deviations in the particle size distribution (PSD), deviations in the presence and composition of a surrounding inorganic shell or even deviations in the surface chemistry have maximum effects on the product properties (absorbance and emission).By means of automatization and rapid sampling the following points shall be covered: i) transfer of complex lab protocols to automatized workflows, ii) exclusion of the human factor to a maximum extend for superior reproducibility at demanding synthesis conditions, iii) establishment of important process-structure-property relationships, iv) fast and efficient screening of large parameter spaces for material development and v) extraction of kinetic parameters for a mechanistic understanding of particle formation. Addressing these aspects is necessary to get an unambiguous understanding at which steps within the process chain from small building blocks towards functional devices quality is lost and how new materials need to be designed and processed for optimum product properties.While the aim of the first funding period is the characterization of the system and the development of rational screening routines, the focus of the second funding period is determined by the development of routines for mechanistic investigations of particle formation processes including nucleation, growth and ripening. In this context, a reasonable high throughput (HT) post-processing in terms of purification and classification needs to be developed as well. Thus, HT particle synthesis will be established as a highly reliable approach for the determination of optimum synthesis protocols.Within the first funding period the following directions shall be followed: First, HT synthesis and HT characterization protocols for both, dispersity in terms of the PSD and product property in terms of the quantum yield (QY) shall be developed. In parallel, a reproducible sampling during early stages of particle formation (< 10 s) will be established. Then, a detailed investigation of the system characteristics in terms of heating and cooling profiles but also with respect to characteristic mixing times shall be realized. The latter are of major importance with respect to the last part of the first funding period where large parameter spaces will be efficiently screened and important process-structure as well as structure-property functions will be established.