Tunable surface plasmon-polariton resonance in organic light-emitting devices based on corrugated alloy electrodes

We report a feasible method to realize tun able surface plasm on-polarit on(SPP)res onance in orga nic light-emitt ing devices(OLEDs)by emplo ying corrugated Ag-Al alloy electrodes.The excited SPP res onance in duced by the periodic corrugations can be precisely tuned based on the composition ratios of the Ag-Al alloy electrodes.With an appropriate composition ratio of the corrugated alloy electrode,the photons trapped in SPP modes are recovered and extracted effectively.The 25%in creaseme nt in luminance and 21%enhan ceme nt in curre nt efficie ncy have bee n achieved by using the corrugated Ag-Al alloy electrodes in OLEDs.

Single-crystalline hole-transporting layers for efficient and stable organic light-emitting devices

Efficient charge-carrier injection and transport in organic light-emitting devices(OLEDs)are essential to simultaneously achieving their high efficiency and long-term stability.However,the charge-transporting layers(CTLs)deposited by various vapor or solution processes are usually in amorphous forms,and their low charge-carrier mobilities,defectinduced high trap densities and inhomogeneous thickness with rough surface morphologies have been obstacles towards high-performance devices.Here,organic single-crystalline(SC)films were employed as the hole-transporting layers(HTLs)instead of the conventional amorphous films to fabricate highly efficient and stable OLEDs.The highmobility and ultrasmooth morphology of the SC-HTLs facilitate superior interfacial characteristics of both HTL/electrode and HTL/emissive layer interfaces,resulting in a high Haacke’s figure of merit(FoM)of the ultrathin top electrode and low series-resistance joule-heat loss ratio of the SC-OLEDs.Moreover,the thick and compact SC-HTL can function as a barrier layer against moisture and oxygen permeation.As a result,the SC-OLEDs show much improved efficiency and stability compared to the OLEDs based on amorphous or polycrystalline HTLs,suggesting a new strategy to developing advanced OLEDs with high efficiency and high stability.

Mechanically robust stretchable organic optoelectronic devices built using a simple and universal stencil-pattern transferring technology

Stretchable electronic and optoelectronic devices based on controllable ordered buckling structures exhibit superior mechanical stability by retaining their buckling profile without distortion in repeated stretch-release cycles.However,a simple and universal technology to introduce ordered buckling structures into stretchable devices remains a real challenge.Here,a simple and general stencil-pattern transferring technology was applied to stretchable organic lightemitting devices(SOLEDs)and polymer solar cells(SPSCs)to realize an ordered buckling profile.To the best of our knowledge,both the SOLEDs and SPSCs with periodic buckles exhibited the highest mechanical robustness by operating with small performance variations after 20,000 and 12,000 stretch-release cycles between 0%and 20%tensile strain,respectively.Notably,in this work,periodic-buckled structures were introduced into SPSCs for the first time,with the number of stretch-release cycles for the SPSCs improved by two orders of magnitude compared to that for previously reported random-buckled stretchable organic solar cells.The simple method used in this work provides a universal solution for low-cost and high-performance stretchable electronic and optoelectronic devices and promotes the commercial development of stretchable devices in wearable electronics.