Constructing high efficiency non-fullerene all-small-molecule ternary organic solar cells by employing structurally similar acceptors. (20th December 2020) - Huang, Ziyun
Abstract : Constructing high efficiency non-fullerene all-small-molecule ternary organic solar cells by employing structurally similar acceptors. Abstract : Significant progress has been made in organic solar cells over the past few years. However, the power conversion efficiency of all-small-molecule systems is still lower than that of polymer photovoltaics. Ternary strategies lead to a potential way to improve the performance of all-small-molecule organic solar systems. In this article, an all-small-molecule ternary organic solar cell is presented by incorporating a small amount of the IDIC acceptor into a ZR1-Cl : IDIC-4Cl based binary system. On the basis of the enhanced absorption spectrum, the good miscibility enabled by two structurally similar acceptors can potentially form receptor alloys, leading to a simultaneous increase in both short circuit current density and open circuit voltage to 18.64 mA cm −2 and 0.90 V, respectively. Characterizations such as transmission electron microscopy and grazing-incidence wide-angle scattering confirmed good miscibility, ordered packing and high crystallinity in the ternary film with a fibrous structure that benefits electron transfer, increasing the fill factor to 69.66%. The simultaneous increment in short circuit current, open circuit voltage and fill factor increases the power conversion efficiency from 10.81% in the binary system to 11.65% in the ternary system.