Fig. 2: Outcoupling efficiency enhancement by the solvent-engineering approach.
From: Grain engineering for efficient near-infrared perovskite light-emitting diodes
a Device and perovskite (PVSK) film morphology were modeled in 3D-FDTD simulation. A single cell (size: P) contains one perovskite grain simplified as a tetragonal block embedded in TFB with defined length (l) and height (H). The curvature atop TFB was simplified as a convex dome defined by the convex height (hs). Due to the high reflectivity of MoOx/Au, each convex dome serves as an intrinsic lens to focus the perovskite emission and prevent unwanted scattering, thus enhancing the total OCE. b To model this effect, a single-cell simulation was carried out while varying the convex geometry hs. The alternative model based on conventional continuous perovskite layer was also studied as the control. An initial quantum OCE jump was observed from continuous film to discrete islands. c The single-cell was expanded to a 9 × 9 periodic grain distribution to estimate the real-scale OCE while modeling the effects from solvent mixture, packing density (α), and H. d Demonstration of the SEM deconstruction process to obtain grain distribution parameters such as P and α as well as to extract real grain distribution, which was then modeled in e to estimate the real device OCEs (scale bar: 1 μm).
