Silicon Naphthalocyanine Tetraimides: Cathode Interlayer Materials for Highly Efficient Organic Solar Cells

Abstract

Naphthalocyanine derivatives (SiNcTI-N and SiNcTI-Br) were firstly used as excellent cathode interlayer materials (CIMs) in organic solar cells, via introducing four electron-withdrawing imide groups and two hydrophilic alkyls. Both of them showed deep LUMO energy levels (below -3.90 eV), good thermal stability (T_d >210 °C), and strong self-doping property. The SiNcTI-Br CIM displayed high conductivity (4.5×10^-5 S cm^-1 ) and electron mobility (7.81×10^-5 cm² V^-1 s^-1 ), which could boost the efficiencies of the PM6:Y6-based OSCs over a wide range of CIM layer thicknesses (4-25 nm), with maximum efficiency of 16.71 %.