Enhanced efficiency of polymer solar cells by structure-differentiated silver nano-dopants in solution-processed tungsten oxide layer

Graphical abstract: - Highlights: • Incorporating different structures of Ag NPs in solution-processed WO₃ layer. • The LSPR effect of metallic nanoparticles is represented by FDTD method. • Enhanced PCE are greatly increased by the LSPR effect of SiAgP and nAgPl. • Naked Ag nanoparticles decreased the PCE of PSCs due to the interface excitons quenching. • Avoiding interface excitons quenching is greatly needed for utilizing metallic NPS in PSCs. - Abstract: In this article, we creatively incorporate naked Ag nanoparticles (nAgp), SiO₂-covered Ag nanoparticles (SiAgp), and naked Ag nanoplates (nAgPl) into solution-processed tungsten oxide (WO₃) hole transport layer in polymer solar cells (PSCs) to increase the light absorption through localized surface plasmon resonance (LSPR) effect. With optimized doping concentrations, nAgp decreases power conversion efficiency (PCE), however, SiAgp increases PCE by 13.2% and nAgPl increases PCE by 19.7%. In detail, the great PCEs discrepancies are mainly caused by the discrepancies of short circuit currents (J_sc). The experiments results indicate that the naked surface of nAgp causes the exciton-quenching to decrease the J_sc of PSCs. Whereas the capsulation of SiO₂ at the surface of nAgp and the embedment of nAgPl in WO₃ layer can prevent the exciton-quenching and help to use LSPR effect of Ag nano-dopants to enhance the J_sc of PSCs.