Hot-injection has become the most widespread method used for the synthesis of perovskite quantum dots (QDs) with enormous interest for application in optoelectronic devices. However, there are some aspects of the chemistry involved in this synthesis that have not been completely investigated. In this work, we synthesized ultra-high stable CsPbI₃ QDs for more than 15 months by controlling two main parameters: synthesis temperature and the concentration of capping ligands. By increasing the capping ligand concentration during the QD synthesis, we were able to grow CsPbI₃ in a broad range of temperatures, improving the photophysical properties of QDs by increasing the synthesis temperature. We achieved the maximum photoluminescence quantum yield (PLQY) of 93% for a synthesis conducted at 185 °C, establishing an efficient surface passivation to decrease the density of non-radiative recombination sites. Under these optimized synthesis conditions, deep red LEDs with an External Quantum Efficiency (EQE) higher than 6% were achieved. The performance of these LEDs is higher than that of the reported CsPbI₃ QD-LEDs containing standard capping agents, without additional elements or further element exchange. We show that it is possible to produce stable CsPbI₃ QDs with high PLQY and red emission beyond the requirement of the Rec. 2020 standards for red color.

中文翻译：

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配体和带隙工程：定制协议合成以实现高质量的CsPbI3量子点。

热注入已成为用于合成钙钛矿量子点（QD）的最广泛方法，其在光电器件中的应用引起了极大兴趣。但是，该合成中涉及的化学反应的某些方面尚未完全研究。在这项工作中，我们通过控制两个主要参数：合成温度和封端配体的浓度，合成了超过15个月的超高稳定性CsPbI ₃ QD。通过在QD合成过程中增加封端配体的浓度，我们能够生长CsPbI ₃在较宽的温度范围内，通过提高合成温度来改善量子点的光物理性质。对于在185°C进行的合成，我们实现了93％的最大光致发光量子产率（PLQY），从而建立了有效的表面钝化作用以降低非辐射复合位点的密度。在这些优化的合成条件下，获得了外部量子效率（EQE）高于6％的深红色LED。这些LED的性能高于已报道的包含标准封端剂的CsPbI ₃ QD-LED，无需额外的元素或进一步的元素交换。我们表明，有可能生产出稳定的CsPbI ₃ QD，具有高PLQY和红色发射，超过Rec。的要求。2020年红色标准。