Bridging for Carriers by Embedding Metal Oxide Nanoparticles in the Photoactive Layer to Enhance Performance of Polymer Solar Cells

Carrier collection and light absorption is a couple of contradiction for polymer solar cells (PSCs) because of the limited carrier mobility and optical absorption coefficient for the organic active layers. In this article, the concept of “bridging for carriers” is introduced by embedding metal oxide (ZnO for electrons and NiO
_x
for holes in this study) nanoparticles into the photoactive layer of PSCs to improve exciton separation, enhance carrier transport, reduce electron-hole recombination and thus facilitate carrier collection. It is found that ~57.6% increase in the power conversion efficiency, i.e., from 1.98% to 3.12% for the optimal addition of ZnO and NiO
_x
into the active layer of the P3HT:PC
₆₁
BM blend is achieved as compared with the control case without adding ZnO and NiO
_x
nanoparticles. In combination with the simple hydrothermal method of preparing these metal oxide nanoparticles, this study is believed to provide valuable contribution to explore facile approaches to address the contradiction of carrier collection and light absorption for PSCs by bridging for carriers in the photoactive layer.