Researchers from Ulsan National Institute of Science and Technology (UNIST) demonstrated high-performance polymer solar cells (PSCs) with power conversion efficiency (PCE) of 8.92%. This is the highest value 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 flexible, lightweight (which is important for small autonomous sensors), solution processability (potentially disposable), inexpensive to fabricate (sometimes using printed electronics), 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.
Although these many advantages, PSCs currently suffer from a lack of enough efficiency for large scale applications and stability problems, but their promise of extremely cheap production and high efficiency values has led them to be one of the most popular fields in solar cell research.
To maximize PCE, light absorption in the active layer has to be increased using thick bulk heterojunction (BHJ) films. However, the thickness of the active layer is limited by the low carrier mobilities of BHJ materials. Therefore, it is necessary to find the ways to minimize the thickness of BHJ films while maximizing the light absorption capability in the active layer.
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. The multi-positional property refers to the ability of Ag@SiO2 NPs to be introduced at both ITO/PEDOT:PSS (type I) and PEDOT:PSS/active layer (type II) interfaces in polymer: fullerene-based BHJ PSCs due to the silica shells.
Because PSCs have many advantages PSCs can be adopted in various applications. However, we should break the efficiency barrier of 10% for commercialization of PSCs.
This story is reprinted from material from XXX, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.