High-Performance Organic Solar Cells with Broadband Absorption Enhancement and Reliable Reproducibility Enabled by Collective Plasmonic Effects

Broadband absorption enhancement in metal nanomaterials for high-performance organic solar cells (OSCs) is highly desirable in the plasmonic-enhanced OSCs. Here, a new dual plasmonic device is proposed by strategically designing device structures and managing two types of plasmonic structures (e.g., metal grating and metal nanoparticles (NPs)) in one device to achieve the broadband enhancement with better reproducibility, including (a) selecting Ag grating with 600 nm period as an anode, (b) introducing metal NPs into the electron transport layer (not active layer), and (c) adopting ZnO as the electron transport layer (not TiO₂). The device shows broadband absorption enhancement in the range of 350-800 nm due to multiple plasmonic effects. As a result, the maximum power conversion efficiency (PCE) of 9.62% has been achieved from the device, which is one of the highest efficiencies in plasmonic OSCs reported for a single junction OSC. Importantly, the as-proposed dual device in this work shows an excellent reproducibility of high PCE in experiment, which is much more applicable for practical applications. This work demonstrates the significance of rational design of the device structure and plasmonic nanostructures in achieving high-performance plasmonic OSCs with broadband plasmonic absorption enhancement and reliable reproducibility. A significant enhancement of organic solar cell (OSC) performance from a power conversion efficiency (PCE) = 7.7% up to a maximum of 9.62% is reported, which is one of the highest efficiencies for plasmonic OSCs reported thus far for a single junction OSC. Importantly, the as-proposed device shows an excellent reproducibility of these devices, which is more applicable for the practical application.