Bridging for Carriers by Embedding Metal Oxide Nanoparticles in the Photoactive Layer to Enhance Performance of Polymer Solar Cells
Zonghao Wu, Wenjie Zhang, Caidong Xie, Li Zhang, Yanzhou Wang, Yahui Zhang, Qiming Liu, Yujun Fu, Yali Li, Junshuai Li, Deyan He
Abstract
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 <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> 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 <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> into the active layer of the P3HT:PC <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">61</sub> BM blend is achieved as compared with the control case without adding ZnO and NiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> 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.