Rational adjustment to interfacial interaction with carbonized polymer dots enabling efficient large-area perovskite light-emitting diodes

Abstract

Film uniformity of solution-processed layers is the cornerstone of large-area perovskite light-emitting diodes, which is often determined by the ‘coffee-ring effect’. Here we demonstrate a second factor that cannot be ignored is the solid-liquid interface interaction between substrate and precursor and can be optimized to eliminate rings. A perovskite film with rings can be formed when cations dominate the solid-liquid interface interaction; whereas smooth and homogeneous perovskite emitting layers are generated when anions and anion groups dominate the interaction. This is due to the fact that the type of ions anchored to the substrate can determine how the subsequent film grows. This interfacial interaction is adjusted using carbonized polymer dots, who also orient the perovskite crystals and passivate their buried traps, enabling a 225 mm2 large-area perovskite light-emitting diode with a high efficiency of 20.2%.

Highly Efficient and Flexible Perovskite Nanocrystal Light-Emitting Diodes on Disposable Paper Substrates

“…Obviously, the roughness 3a,b, including a small area (4 mm 2 ) and large area (150 mm 2 ) device, indicating outstanding film-forming ability of devices on the label/PMMA substrate. 37 To compare the mechanical robustness of flexible PeLEDs based on label paper/PMMA and PET substrates, the EL spectra of both devices under different bending cycles with a small bending radius (r b ) of 1.5 mm were measured (Figure 3c,d). With the increase of bending times, the EL spectra of both devices did not shift significantly, but PET-based devices were damaged after bending 150 times.…”

“…The photographs of label paper/PMMA-based PeLEDs are shown in Figure a,b, including a small area (4 mm 2 ) and large area (150 mm 2 ) device, indicating outstanding film-forming ability of devices on the label/PMMA substrate . To compare the mechanical robustness of flexible PeLEDs based on label paper/PMMA and PET substrates, the EL spectra of both devices under different bending cycles with a small bending radius ( r b ) of 1.5 mm were measured (Figure c,d).…”

Low‐Dimensional Phase Distribution of Quasi‐2D Perovskites Induced by Interfacial Effect Enables Efficient Blue Lighting‐Emitting Diodes

“…The increase of glycine resulted in a gradual decrease in the conductivity of the PEDOT:PSS films, which could be ascribed to a reduced phase separation between PEDOT and PSS phases (Figure S4, Supporting Information). [ 34,35 ] Moreover, the presence of glycine also changed the surface property of PEDOT:PSS films. The contact angles of the perovskite precursor solution toward the P‐PEDOT:PSS and Gly‐PEDOT:PSS films were measured and the results are shown in Figure 1b and Figure S6 (Supporting Information).…”

Low-dimensional nanomaterial-enabled efficient and stable perovskite light-emitting diodes: recent progress and challenges

“…4c). 76 Yan et al mixed the PEDOT:PSS HTL with a graphene quantum dots (GQDs) made of chitin to tune the highest occupied molecular orbital of PEDOT:PSS and improve carrier transmission efficiency (Fig. 4d).…”