Colloidal PbS quantum dots (QDs) are promising candidates for various optoelectronic applications based on solution-processed thin-film techniques. In this work, a versatile layer-by-layer (LBL) spray deposition of the QDs is introduced aiming for a future large-scale fabrication process of optoelectronic devices. As compared to spin-coated QD solids, a smaller inter-dot distance and a better-ordered superlattice stacking behavior of the QDs are found in the spray-deposited QD solids as confirmed by grazing-incidence small-angle X-ray scattering (GISAXS). The spectral mapping combined time-resolved photoluminescence analysis indicates a longer charge carrier lifetime and better order of the energy state distribution of the spray-deposited QD solid comparing with the spin-coated one. Thus, photodetectors based on spray deposition of QD solids demonstrate an excellent device performance, with the responsivity achieving 365.1 A/W and the detectivity reaching up to 1.4 × 10¹² Jones under an illumination power of 63.5 μW/cm² at a wavelength of 1250 nm. The spray-deposited device performances indicate a great potential of spray deposition of large sized QDs in large-scale fabrications for optoelectronics using longer wavelengths.

胶体PbS量子点（QDs）是基于溶液处理薄膜技术的各种光电应用的有希望的候选者。在这项工作中，引入了QD的通用逐层（LBL）喷涂沉积，旨在用于未来的光电器件大规模制造工艺。与旋涂QD固体相比，在喷涂沉积的QD固体中发现了更小的点间距离和更好的超晶格堆叠行为，这一点已通过掠入射小角度X射线散射（GISAXS）证实了）。光谱映射结合时间分辨的光致发光分析表明，与旋涂的固体相比，喷雾沉积的QD固体具有更长的电荷载流子寿命和更好的能态分布顺序。从而，¹² Jones在1250 nm波长的照明功率为63.5μW/ cm ^2的情况下。喷雾沉积的器件性能表明，在使用较长波长的光电子大规模生产中，大型QD的喷雾沉积潜力很大。