| 초록 |
Methylammonium lead halide perovskites have been intensively studied as promising photo absorption in solar cells and an alternative emitters in light emitting diodes (LEDs). However, lower work function (WF) of PEDOT:PSS (4.8 eV) comparing with ionization potential (IP) of perovskite (5.4 ~ 5.9 eV) decreased the built-in potential in solar cells and efficiency in LEDs. Thus we used a self-organized hole injection/extraction buffer layer which is composed of a PEDOT:PSS and a perfluorinated ionomer (PFI), i.e., tetrafluoroethylene-perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid copolymer to reduce the energy level difference between WF of PEDOT:PSS and IP level of perovskites. We obtained high PCE of 11.7% in solution-processed planar heterojunction perovskite solar cells under 100-mW/cm2 illumination. We also demonstrated high efficiency (417 cd/m2, 0.577 cd/A, 0.125%) and multicolored perovskite light-emitting diodes. |
