Fig. 1: Quantum dots and device structure.
a Illustration of the QD structure. b TEM image of QDs (scale bar = 10 nm). c Illustration and cross-sectional TEM image of the top-emitting QLED structure (scale bar = 100 nm). d SEM images of QD layers’ surface morphology. The conventional and index-lowering processes result in nanocrystal areal densities of 53.5 ± 1.6 and 47.8 ± 2.0 per 10,000 nm2 within the dashed box, respectively. The arrows point to some of the gaps between QDs caused by the index-lowering processes (scale bar = 100 nm). e Refractive indices of nanocrystal-assembled films formed using the conventional method and index-lowering process. f Schematic diagram of one-dimensional field distribution inside a λ/2 cavity.
