초록 |
A polymeric hole transporting material(HTM) with proper HOMO level and high hole mobility was succesfully applied to perovskite solar cells. Poly[2,5-bis(2-decyldodecyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-(E)-1,2-di(2,2’-bithiophen-5-yl) ethene] (PDPPDBTE) was incorporated as a p-type HTM. The excellent optical and electrical properties of organo-lead halide perovskite nanocrystals used as a light harvester yielded a 9.2% power conversion efficiency (PCE) for the best-performing cell that exceeded the value (7.6%) obtained from the best hole conductor yet reported (2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9'-spirobifluorene, spiro-MeOTAD). The high PCE was attributed to the optimal oxidation potential (5.4 eV) and excellent charge carrier mobility of the polymer. The hydrophobicity of the polymer prevented water permeation into the porous perovskite heterojunction, and long-term aging tests over 1000 hours confirmed the enhanced stability of the PDPPDBTE-based cells. |