A Giant Leap to Commercialization of Polymer Solar Cell (PSC)
(a) Device structures, (b) J−V characteristics, and (c) EQE of PTB7:PC70BM-based PSCs with type I and type II architectures (Top)(a) Device structures and (b) reflectance spectra of PTB7:PC70BM-based PSCs with different spatial locations of Ag@SiO2 (Bottom) (Image credit: Ulsan National Institute of Science and Technology)
Researchers from Ulsan National Institute of Science and Technology (UNIST) have demonstrated high-performance polymer solar cells (PSCs) with a power conversion efficiency (PCE) of 8.92% --the highest values reported to date for plasmonic PSCs using metal nanoparticles (NPs). A polymer solar cell is a type of thin film solar cells made with polymers that produce electricity from sunlight by the photovoltaic effect. Most current commercial solar cells are made from a highly purified silicon crystal. The high cost of these silicon solar cells and their complex production process has generated interest in developing alternative photovoltaic technologies. Compared to silicon-based devices, PSCs are lightweight (which is important for small autonomous sensors), solution processability (potentially disposable), inexpensive to fabricate (sometimes using printed electronics), flexible, and customizable on the molecular level, and they have lower potential for negative environmental impact. Polymer solar cells have attracted a lot of interest due to these many advantages. But PSCs currently suffer from a lack of enough efficiency for large scale applications and stability problems -- but their promise of extremely cheap production and eventually high efficiency values has led them to be one of the most popular fields in solar cell research. The research team employed the surface plasmon resonance (SPR) effect via multi-positional silica-coated silver NPs (Ag@SiO2) to increase light absorption. The silica shell in Ag@SiO2 preserves the SPR effect of the Ag NPs by preventing oxidation of the Ag core under ambient conditions and also eliminates the concern about exciton quenching by avoiding direct contact between Ag cores and the active layer.