Highly Robust, Flexible Top‐Emission Organic Light‐Emitting Diode Exhibiting Stable Performance under Infolding of Curvature Radius of 0.32 mm

Abstract

Flexible top‐emission organic light‐emitting diodes (TOLEDs) with a thin‐film encapsulation (TFE) are of increasing attention to improve the flexibility of foldable smartphone organic light‐emitting diode (OLED) displays. There are inevitable issues to achieve foldable display with smaller folding radius for the future portable display. Herein, the device flexibility is investigated with infolding and outfolding tests with the curvature radius from 2.5 to 0.32 mm. Parylene (1 μm)/silicon nitride (SiNx) (X nm)/parylene (1 μm)/SiNx (X nm) (X = 100, 70, 50, and 30 nm) of TFEs are applied on the TOLEDs. It is found that stable device performances can be achieved at the curvature radius of 0.32 mm after 100 000 cycles infolding testing when the SiNx thickness is 30 nm. The device has significant degradation upon outfolding of 5000 cycles at the same radius of 0.32 mm. Note that, the water vapor transmission rate (WVTR) of the TFT with 30 nm SiNx is higher than the TFE with thicker SiNx (e.g., 50 nm). The flexibility and WVTR can be much improved using four‐stacked TFE with 30 nm SiNx for foldable active‐matrix OLED displays.

Flexible CdSe/ZnS Quantum-Dot Light-Emitting Diodes with Higher Efficiency than Rigid Devices

“…Most existing flexible displays employ organic light-emitting diodes (OLEDs). Foldable smartphones with OLED displays [1][2][3] are becoming widely available and the first rollable televisions [4] have appeared on the market. Flexible displays widen the applications of electronic displays and greatly reduce manufacturing costs, as they allow for roll-to-roll fabrication [5].…”

Complete stress release in monolayer ALD-Al2O3 films based on mechanical equilibrium homeostasis to realize a bending radius of 1 mm

“…Among the many display devices, organic light-emitting diodes (OLEDs), with their ultra-thin, self-emitting, and high-flexibility characteristics, have tremendous market potential for wearable, foldable electronic devices. [3][4][5][6][7] However, OLEDs are rapidly degraded by moisture and oxygen molecules. Currently, chemical vapor deposition (CVD) and atomic layer deposition (ALD) are widely utilized to fabricate encapsulated films.…”