Chen Hsueh-Shih, Chen Cheng-Yang, Wu You-Cneng
Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, 30013, Taiwan.
College of Semiconductor Research, National Tsing Hua University, Hsinchu, 30013, Taiwan.
Adv Mater. 2025 Jan;37(3):e2407026. doi: 10.1002/adma.202407026. Epub 2024 Nov 25.
Indium phosphide (InP) quantum dots (QDs) are increasingly considered potent alternatives to traditional cadmium-based QDs. Notwithstanding, the material stability of InP, especially when juxtaposed with its cadmium-based counterparts, poses significant challenges in its application. Generally, a thick ZnS shell is applied to InP cores to thwart photo-oxidation and diminish nonradiative recombination. Yet, the pronounced lattice mismatch between the InP core and the ZnS shell can introduce lattice defects, consequently attenuating the luminescence efficiency. This makes the cultivation of a flawless thick shell a paramount challenge. In the present research, a synthetic methodology is elucidated to fabricate highly efficient InP QDs with dimensions exceeding 20 nm, achieved by alleviating the lattice mismatch strain during the shell growth. By regulating the shell composition and morphology, InP/ZnSe/ZnSeS/ZnS QDs with shield-like morphology are prepared and demonstrate a photoluminescence quantum yield (PLQY) of ≈90%, exhibiting significantly enhanced photostability and thermal stability. This discovery is expected to greatly advance the preparation of highly efficient InP-based or other QDs, expanding their potential in various applications such as environmentally friendly displays and energy-saving lighting.
磷化铟（InP）量子点（QDs）越来越被认为是传统镉基量子点的有力替代品。尽管如此，InP的材料稳定性，尤其是与镉基量子点相比时，在其应用中带来了重大挑战。通常，会在InP核上包覆一层厚厚的硫化锌（ZnS）壳层，以防止光氧化并减少非辐射复合。然而，InP核与ZnS壳层之间明显的晶格失配会引入晶格缺陷，从而降低发光效率。这使得生长完美的厚壳层成为一项至关重要的挑战。在本研究中，阐明了一种合成方法，通过减轻壳层生长过程中的晶格失配应变，制备出尺寸超过20纳米的高效InP量子点。通过调节壳层组成和形态，制备出具有屏蔽状形态的InP/ZnSe/ZnSeS/ZnS量子点，其光致发光量子产率（PLQY）约为90%，表现出显著增强的光稳定性和热稳定性。这一发现有望极大地推动高效InP基或其他量子点的制备，扩大它们在环保显示器和节能照明等各种应用中的潜力。
