Precursor Route Poly(1,4-phenylenevinylene)-Based Interlayers for Perovskite Solar Cells

Insoluble glycol-derivatized poly(1,4-phenylenevinylene)s (PPVs) have been prepared by in situ thermal conversion of solution-processable xanthate precursor polymers and used as interlayers in inverted perovskite solar cells. The insolubility of the PPVs enabled the perovskite active layer to be deposited on top without dissolution, and the glycol chains provided a suitable surface energy for the formation of the perovskite films. It was found that the surface of the films became more hydrophilic with increasing glycol side-chain length. The energy levels of the PPVs indicated they were appropriate for hole transport and electron blocking with respect to the perovskite layer. The performance of the perovskite cells was found to be dependent on the length of PPV glycol side-chain with the optimized planar p-i-n perovskite devices incorporating an MeO-PPV/PFN-P2 hole-extracting interlayer exhibiting a champion power conversion efficiency of 12.1%.