Inorganic/Organic Electron Transport Interface Engineering for Planar and Fiber-Shaped Organic Solar Cells

Abstract

Using an interfacial modifier (IM) agent to overcome interfacial problems of zinc oxide (ZnO), which is commonly used as an electron transport layer (ETL), is an effective interfacial engineering strategy that can be used to improve the performance and stability of optoelectronic devices, such as inverted organic solar cells (iOSCs). In this work, a conjugated polymer electrolyte (CPE) is employed as an IM agent to modify the surface morphology of ZnO ETL-based iOSC devices. Compared to a pristine ZnO ETL, the CPE-modified ZnO (CPE/ZnO) ETL is more hydrophobic with a smooth surface induced by an interfacial dipole, resulting in better energy alignment to the LUMO of the photoactive layer. The power conversion efficiency (PCE) of poly(3-hexylthiophene) (P3HT) and phenyl-C 60 -butyric acid methyl ester (PCBM) blend-based planar iOSCs with a CPE/ZnO ETL increases from 3.8% to 4.2% and from 1.8% to 2.2% for bottom and top transparent devices, respectively. The CPE/ZnO ETL is further employed to fabricate a fiber-shaped iOSC (FS-iOSC), which is a promising wearable optoelectronic device. In FS-iOSCs fabricated by a dip-coating method with a CPE/ZnO ETL, the PCE improves to 1.02%, which is a near 2-fold improvement over devices using a pristine ZnO ETL. Additionally, our concept has also been successfully applied to inverted polymer light-emitting diodes (iPLED) with planar and fiber-shaped configurations. These results suggest that the surface modification of metal oxide ETLs (e.g., ZnO) with organic interfacial modifiers (e.g., CPE) is a simple but effective approach to fabricating planar and fiber-shaped optoelectronic devices with high performance.

Visible Light-Assisted Charge Extraction in High-Band-Gap SrTiO3 through the Integration of a Triplet Sensitizer–Emitter Thin Film

“…It provides stability and is compatible with a variety of materials, including metal oxides. Furthermore, the electron transport layer (ETL) − and hole transport layer (HTL) − are utilized to facilitate efficient charge separation and transport, reducing the likelihood of charge recombination. Metal oxides, including those used in perovskite solar cells, are commonly employed as ETLs .…”