Highly flexible organic-inorganic hybrid perovskite light-emitting devices based on an ultrathin Au electrode.

Organic-inorganic hybrid perovskite materials have received much attention in light-emitting applications during the past several years. The commonly used indium tin oxide (ITO) electrodes in perovskite light-emitting devices (PeLEDs) have unavoidable drawbacks of increasing cost and incompatibility with flexible devices, which limit the development of PeLEDs. Here, high-performance and ITO-free flexible PeLEDs utilizing ultrathin Au electrodes have been achieved and exhibited high brightness (>10,000  cdm-2 ). By introducing a MoO3 /SU-8 modification layer, the ultrathin Au film with a thickness of 7 nm exhibits excellent surface morphology with a root-mean-square roughness value of 0.307 nm. Meanwhile, the ultrathin Au film demonstrates an outstanding optical property with transparency of 83% at the wavelength of 550 nm. Simultaneously, favorable conductivity with a sheet resistance of 13  Ω sq-1 has been achieved. High mechanical robustness and flexibility have been obtained for the flexible PeLEDs by surviving 1000 bending cycles. The flexible PeLEDs reported here exhibit tremendous potential for commercial applications.