Enhancing the light-harvesting and charge transport properties of polymer solar cells by embedding NaLuF4:Yb,Tm nanorods
Abstract
In this contribution, we study the effects of NaLuF4:Yb,Tm nanorods (NRs) dopant on the performance of inverted polymer bulk heterojunction (BHJ) solar cells. The study allows us to investigate the impact of NRs on the light-harvesting and photocurrent in BHJ solar cells fabricated with PCDTBT blended with [6,6]-phenyl-C71-butyric acid methylester (PC71BM) acceptor. By controlling the doping concentrations, we demonstrate that the power conversion efficiency (PCE) of PCDTBT:PC71BM solar cells increases from 6.02% to 7.18% mainly due to improving light absorption and photocurrent. The single carrier devices reveal that the electron and hole mobilities both rise in doped devices, contributing to the enhancement of photoconductivity and consequent PCEs.