Production of thermoelectric materials from solution‐processed particles involves the synthesis of particles, their purification and densification into pelletized material. Chemical changes that occur during each one of these steps render them performance determining. Particularly the purification steps, bypassed in conventional solid‐state synthesis, are the cause for large discrepancies among similar solution‐processed materials. In present work, the investigation focuses on a water‐based surfactant free solution synthesis of SnSe, a highly relevant thermoelectric material. We show and rationalize that the number of leaching steps, purification solvent, annealing, and annealing atmosphere have significant influence on the Sn:Se ratio and impurity content in the powder. Such compositional changes that are undetectable by conventional characterization techniques lead to distinct consolidated materials with different types and concentration of defects. Additionally, the profound effect on their transport properties is demonstrated. We emphasize that understanding the chemistry and identifying key chemical species and their role throughout the process is paramount for optimizing material performance. Furthermore, we aim to demonstrate the necessity of comprehensive reporting of these steps as a standard practice to ensure material reproducibility.

中文翻译：

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揭示影响溶液加工无机热电材料性能的关键化学加工参数

用溶液加工颗粒生产热电材料涉及颗粒的合成、纯化和致密化成颗粒材料。这些步骤中每一步发生的化学变化都决定了它们的性能。特别是传统固态合成中绕过的纯化步骤，是造成类似溶液加工材料之间存在巨大差异的原因。在目前的工作中，研究重点是水基无表面活性剂溶液合成 SnSe，这是一种高度相关的热电材料。我们证明并合理化了浸出步骤的数量、纯化溶剂、退火和退火气氛对粉末中 Sn:Se 比率和杂质含量的显着影响。这种传统表征技术无法检测到的成分变化导致了具有不同类型和浓度缺陷的不同固结材料。此外，还证明了对其传输特性的深远影响。我们强调，了解化学并确定关键化学物质及其在整个过程中的作用对于优化材料性能至关重要。此外，我们的目标是证明全面报告这些步骤作为标准实践的必要性，以确保材料的可重复性。