Light extraction efficiency enhancement of CH3NH3PbBr3 light-emitting diodes using nanopatterned PEDOT:PSS layers

Nanopatterned poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layers fabricated by soft-nanoimprint were applied to CH3NH3PbBr3 (MAPbBr3) light-emitting diodes to enhance light extraction. The electric field distribution of MAPbBr3 devices with different periods of the nanopatterned PEDOT:PSS was calculated using the finite-difference time-domain method, demonstrating that the 400-nm period was more effective in improving light outcoupling. By integrating the nanopatterned PEDOT:PSS layer, the external quantum efficiency of the device increased from 6.5% to 10.3%. It can be attributed to the fact that the nanopatterned structure reduced the refractive index discontinuity at the interface between MAPbBr3 and PEDOT:PSS, thereby reducing light trapping in the waveguide mode.