PEG修饰的金纳米棒掺入活性层中对有机太阳能电池性能的改善

Organic solar cells (OSCs) have many potential advantages such as easy fabrication, low cost, light weight, good flexibility, etc. However, the power conversion efficiency (PCE) of OSCs is lower than their inorganic counterparts because the thickness of the active layer is limited due to the contradiction between the electrical and optical properties. Aiming for boosting the absorption under the existing thickness of the active layer, researchers have introduced diverse light trapping elements into OSCs, e.g., metallic nanoparticles (MNPs), as they can excite localized surface plasmon resonance. Recently, there have been a series of experimental studies dedicated to understanding the influences of MNPs on the performance of OSCs. In this work, we have successfully synthesized lipophilic Au Nanorods (NRods) by surface modifying the aqueous Au NRods using NH2-PEG-SH and then dope the lipophilic Au NRods directly into the active layer of OSCs. By this way, we have improved the PCE of OSC devices from 5.9% to 6.5%, corresponding to almost 10% improvement. The significant increase in PCE comes from the increase in the short circuit current, agreeing well with the broadband enhancement in the spectra of external quantum efficiency. Besides, the film with PEG-coated Au NRods has greater optical absorption relative to the control film, reflecting that the incorporation of the MNPs helps harnessing more incident light and thus improving PCE.