Highly efficient flexible perovskite light-emitting diodes using the modified PEDOT:PSS hole transport layer and polymer-silver nanowire composite electrode

Metal halide perovskites have been actively studied as promising materials in optoelectronic devices because of their superior optical and electrical properties and have also shown considerable potential for flexible devices because of their good mechanical properties. However, the large hole injection barrier and exciton quenching between the perovskite emitter and poly(3,4-ethylenedioxythiophene):poly-styrene sulfonate (PEDOT:PSS) can lead to the reduction in device efficiency. Here, a nonconductive fluorosurfactant, Zonyl FS-300 (Zonyl), is introduced into the PEDOT:PSS hole transport layer, which reduces the hole injection barrier and exciton quenching at the PEDOT:PSS/perovskite interface. Moreover, a flexible perovskite light-emitting diode with a polymer-silver nanowire composite electrode is demonstrated, showing a maximum current efficiency (CE_max) of 17.90 cd A^-1, and this is maintained even after 1000 cycles of bending with a 2.5 mm bending radius.