Bright, narrow spectrum infrared emitters, particularly Cd- and Pb-free materials, are of interest for bioimaging, photodetection, and telecommunications. InAs-based quantum dots (QDs) are promising emitters in this spectral range; however, efforts to increase the photoluminescence quantum yield (PLQY) tend to broaden the PL line width as a consequence of interfacial defect formation when thick shells, lattice-mismatched with the core, are employed. Here we report that developing a single-precursor complex for InZnP growth enables uniform shell growth that maintains the excellent size dispersion (6%) of the cores. The introduction of this intermediate layer is key to facilitate the subsequent growth of different shells to improve radiative recombination without sacrificing size uniformity. The growth of InAs/InZnP/ZnSe leads to a PL full-width at half-maximum (fwhm) of 100 meV at 1.12 eV with a PLQY of 14%. We then further introduce an additional GaP layer to increase the radiative/nonradiative relative rate. InAs/InZnP/GaP/ZnSe QDs reach a PLQY of 23% while maintaining a narrow fwhm.

中文翻译：

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单前体中间外壳可实现基于InAs / InZnP的QD发射器的明亮，窄线宽

明亮，窄谱的红外发射器，特别是无Cd和Pb的材料，对于生物成像，光电检测和电信领域非常重要。基于InAs的量子点（QD）在此光谱范围内很有希望。然而，当采用厚晶格与核不匹配的厚壳时，由于界面缺陷的形成，增加光致发光量子产率（PLQY）的努力倾向于加宽PL线宽。在这里，我们报道开发用于InZnP生长的单前体复合物可以使壳均匀生长，从而保持出色的核尺寸分散度（6％）。引入该中间层是促进不同壳随后生长以改善辐射复合而不牺牲尺寸均匀性的关键。InAs / InZnP / ZnSe的生长导致在1.12 eV处的半高（fwhm）处的PL全宽为100 meV，PLQY为14％。然后，我们进一步引入额外的GaP层，以增加辐射/非辐射相对速率。InAs / InZnP / GaP / ZnSe量子点的PLQY达到23％，同时保持较低的重量。