Water Passivation of Perovskite Nanocrystals Enables Air‐Stable Intrinsically Stretchable Color‐Conversion Layers for Stretchable Displays

Abstract

Conventional organic light‐emitting devices without an encapsulation layer are susceptible to degradation when exposed to air, so realization of air‐stable intrinsically‐stretchable display is a great challenge because the protection of the devices against penetration of moisture and oxygen is even more difficult under stretching. An air‐stable intrinsically‐stretchable display that is composed of an intrinsically‐stretchable electroluminescent device (SELD) integrated with a stretchable color‐conversion layer (SCCL) that contains perovskite nanocrystals (PeNCs) is proposed. PeNCs normally decay when exposed to air, but they become resistant to this decay when dispersed in a stretchable elastomer matrix; this change is a result of a compatibility between capping ligands and the elastomer matrix. Counterintuitively, the moisture can efficiently passivate surface defects of PeNCs, to yield significant increases in both photoluminescence intensity and lifetime. A display that can be stretched up to 180% is demonstrated; it is composed of an air‐stable SCCL that down‐converts the SELD’s blue emission and reemits it as green. The work elucidates the basis of moisture‐assisted surface passivation of PeNCs and provides a promising strategy to improve the quantum efficiency of PeNCs with the aid of moisture, which allows PeNCs to be applied for air‐stable stretchable displays.

Wavelength-Tunable and Water-Stable Cesium–Lead-Based All-Bromide Nanocrystal–Polymer Composite Films Using Ultraviolet-Curable Prepolymer as an Anti-Solvent

“…Recently, IPeNCs have been composited with polymers to enhance their stability against moisture, light, and heat. Compared with other techniques, blending IPeNCs with a commercial polymer, such as polymethylmethacrylate, poly(laurylmethacrylate), polydimethylsiloxane, polystyrene, poly(styrene-ethylene-butylene-styrene), and thermoplastic polyurethane, is a relatively easy and effective method for protecting IPeNCs [21][22][23][24][25][26][27]. However, during the time-consuming blending process in air, IPeNCs often decompose and agglomerate owing to the large difference in the polarity between the IPeNCs and polymers.…”

Tough, stable and self-healing luminescent perovskite-polymer matrix applicable to all harsh aquatic environments

“…5e, the normalized PLQY value (PLQY/PLQY initial ) kept stable without obvious decay after 1 month of immerging. The increase of PLQY at the beginning was probably attributed to surface passivation of a minor amount of water 41,42 . This was also verified by the comparison of PL lifetimes before and after aging in water and other aqueous conditions (Fig.…”

Defect Behaviors in Perovskite Light-Emitting Diodes

“…72 The moisture passivation effect is closely related to the type of cations present in perovskites. 76 The organic cations MA + and FA + contained in hybrid perovskites are extremely sensitive to moisture and, thus, have a tendency to degrade LEDs performance. 77 The degradation of MAPbI 3 upon exposure to moisture (Figure 4a) is considered to be a major factor in perovskite solar cells failure.…”

“…During the synthesis process, moisture can form an inorganic matrix that completely wraps the perovskite and passivates surface defects . The moisture passivation effect is closely related to the type of cations present in perovskites . The organic cations MA + and FA + contained in hybrid perovskites are extremely sensitive to moisture and, thus, have a tendency to degrade LEDs performance .…”