Two-Dimensional Stretchable Organic Light-Emitting Devices with High Efficiency.

Stretchable organic light-emitting devices (SOLEDs) with two-dimensional (2D) stretchability are superior to one-dimensional (1D) SOLEDs in most practical applications such as wearable electronics and electronic skins and therefore attract a great deal of interest. However, the luminous efficiency of the 2D SOLEDs is still not practical for the purposes of commercial applications. This is due to the limitations on materials and structures from the physical and electrical damage caused by the complicated interactions of the anisotropic stress in 2D stretchable system. Here 2D SOLEDs with excellent stretchability and electroluminescence performance have been demonstrated based on an ultrathin and ultraflexible OLED and a buckling process. The devices endure tensile strain of 50% in area with a maximum efficiency of 79 cd A, which is the largest luminescent efficiency of 2D SOLEDs reported to date. The 2D SOLEDs survive continuous cyclic stretching and exhibit slight performance variations at different strain values. The 2D SOLEDs reported here have exhibited enormous potential for various practical applications.