Synthesis, characterization and photocell studies of a Pt(II) poly-yne covalently attached to a fullerene

Conjugated polymer solar cells (PSCs) use the principle of exciton dissociation at the interface of suitable donor and acceptor materials. However, this requires good phase separation between the two materials, which is often difficult to achieve. To circumvent such difficulties, we have covalently attached a C₆₀ derivative (C₆₀-DNF) to a Pt(II) poly-yne (P1) incorporating 2-amino-1,4-phenylene spacer. The fullerene-linked Pt(II) poly-yne (P2) was characterized by analytical, spectroscopic and GPC methods. We fabricated photocells using P2 and compared the performance of the photocells to those of conventional blends of P1 and C₆₀. We found that P2 shared similar photocurrent quantum yield and spectral response to those of the blends. Photoluminescence measurements indicate a better charge separation in P2 but for an optimized percolation path, a higher ratio of C₆₀ in the Pt(II) poly-yne backbone is needed. Results of quantum chemical calculation complemented experimental results of energy band gap and supports the suitability of fullerene-linked Pt(II) poly-yne for photocell applications.