Green poly-lysine as electron-extraction modified layer with over 15% power conversion efficiency and its application in bio-based flexible organic solar cells
Journal
Organic Electronics
Journal Volume
87
Date Issued
2020
Author(s)
Abstract
In this study, we first revealed a green material-Poly-lysine as an interfacial layer (IFL) of electron-extraction layer (EEL) and investigated evolution of morphologies of the active layers in organic photovoltaics (OPVs). The surface structure of the active layers was characterized by atomic force microscopy (AFM) and the molecular packing features were revealed by grazing-incidence wide-angle X-ray scattering (GIWAXS). By embedding poly-lysine as IFL, we evidenced the changes of the blend film phase segregation and observed an increase order of molecular packing in preferential face-on orientation. The optimized blend film morphology facilitated the carrier extraction, thereby significantly improved the OPV performance with the best power conversion efficiency (PCE) of 12.5% and 15.3% for the PBDB-T-2Cl:IT-4F and PBDB-T-2F:Y6 blends, respectively. Compared with the controlled devices, the poly-lysine-modified devices showed significantly improved thermal-and photo-stability which keeps 80% of its initial efficiency after 400-h heating and illumination. As the first discovery of its general applicability of the promising IFL material, poly-lysine was further applied to fabricate a flexible OPV device using 100% bio-based polyethylene furandicarboxylate (PEF) substrate and its derived OPV device exhibited a PCE greater than 7% and maintained the 80% efficiency under the high bending radius of 3 mm. The present study suggests the potential application of using bio-based materials for flexible OPV applications. © 2020 Elsevier B.V.
Subjects
Biomaterials; Interfacial modifications; Long-term stability; Organic photovoltaic cells; Renewable flexible substrate
SDGs
Other Subjects
Amino acids; Atomic force microscopy; Conversion efficiency; Efficiency; Image enhancement; Molecular orientation; Morphology; Organic solar cells; Surface structure; X ray scattering; Bio-based materials; Electron extraction; Evolution of morphologies; Flexible organic solar cells; Initial efficiency; Molecular packings; Organic photovoltaics; Power conversion efficiencies; Extraction
Type
journal article