Copper ion-modified oxyl-terminated melem nanodisks for enhanced performance of organic and perovskite solar cells

Abstract

The limited charge extraction efficiency and suboptimal energy-level alignment of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as a hole transport layer restrict its performance in solar cell applications. In this study, we developed effective copper-ion (Cu(II))-modified oxyl-terminated melem two-dimensional (2D) nanodisks (Cu(II)@OMN) that improved the performance of PEDOT:PSS as a representative hole-transport layer (HTL) in organic and perovskite solar cells. Based on theoretical calculations and experimental data, the interaction between Cu(II)@OMN and PEDOT or PSS led to electron redistribution in PEDOT:PSS and the dissociation of PEDOT and PSS, promoting enhanced charge extraction and transfer. In addition, the work function of the Cu(II)@OMN-PEDOT:PSS is modified to achieve a more beneficial energy-level alignment, thereby facilitating improved hole transport and inhibited nonradiative recombination. Methylammonium (MA)-based perovskite and organic binary PM6:Y6 solar cells achieved power conversion efficiencies (PCEs) of 19.21% and 17.15%, respectively. These PCEs are among the highest reported for MA-based perovskite and binary PM6:Y6 organic solar cells that use 2D nanomaterial-modified PEDOT:PSS, demonstrating the potential of Cu(II)@OMN in solar cell applications.