Nanocore Shells for Effective Collection of Photocurrent in Polymer Solar Cell

Charge transport process is one of the most important factors that determine the performance of thin‐film organic solar cells. In this report, nanocore shells (NCSs) composed of a copper core and nickel as a shell (Cu@Ni) are successfully synthesized and used in the functional layer of thin‐film organic solar cell (TFOSC). The NCSs are doped in the hole‐selective material known as poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate at various concentrations from 0.1% to 0.5% by weight. Bulk heterojunction solar absorber design is used to fabricate new polymer solar cells using poly‐3‐hexylthiophene as a donor and [6,6] phenyl‐C61‐butyric acid methyl ester as an acceptor. The experimental results suggest that the device performances of the samples doped with Cu@Ni NCSs have significantly improved compared to the reference cell. The collection of high photocurrents is responsible for improved device performance as a result of better optical absorption and charge transport processes. Furthermore, the performances are found to be dependent on concentration of NCS in the transport layer. The best performance recorded in the study is found to be at the 0.2 wt% doping level. Such improvements in power conversion efficiency are attributed to the occurrence of local surface plasmon resonances on the NCS in the polymer transport layer.