Polymer-Based Anti-Solvent Engineering to Fabricate Stable and Efficient Triple-Cation Perovskite Solar Cells

摘要

Perovskite materials, due to their excellent photovoltaic features, have aroused the researchers’ admiration as a photon- absorption film for the next-generation photovoltaics. The interface tailoring of perovskites and hole-transport layer (HTL) is one of the critical approaches to achieve effective and stabilized perovskite solar cell (PSC). Hence, poly[4,8-bis[(2- ethylhexyl)oxy]benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl][3-fluoro- 2-[(2 ethylhexyl)carbonyl]thieno[3,4-b]-thiophenediyl] (PTB7) as a polymeric organic semiconductors was employed for doping of anti-solvent solution to modify the perovskite film. Results showed with PTB7 dopant; grain boundaries (GBs) of the perovskites are reduced. It suppressed carriers’ trap centers in the perovskite film and decreased recombination processes within perovskite layers. Besides, the high intrinsic conductivity of PTB7 material assisted charge injection at the perovskites/ HTL interfaces and hindered carrier’s accumulation. The device with PTB7 showed a more matched energy level and a higher prevention for recombination than the device without PTB7 dopant, which are reasons for the considerable boost in the open-circuit voltage (VOC) and fill-factor (FF), giving rise a power conversion efficiency (PCE) of 19.18% for the champion performing PVs. Most important, the hydrophobic origin of PTB7 leads to superb humidity stability in the device with PTB7 dopant with 85% of the original performance remaining after more than 800 h storing in air with -40% RH.