Broadband Absorption Enhancement in Polymer Solar Cells Using Highly Efficient Plasmonic Heterostructured Nanocrystals.

Raising the light absorption of the photoactive layer in polymer solar cells (PSCs) without increasing the layer thickness is desirable but challenging because of the low carrier mobility of organic materials. Herein, we used the coupled localized surface plasmon resonance of heterostructured Au-Cu2- xS nanocrystals (NCs) to improve the light-trapping capability of the photoactive layer of PSCs. Broadband light absorption and a considerable improvement of the power conversion efficiency were obtained when the photoactive layer was doped with a tiny amount of NCs. This can be explicated by the enhanced near-field intensity and broadband scattering properties of added NCs.