Molecular design and application of novel small molecule organic dyes featuring bis(arylvinyl)phenyl amino group for dye-sensitized solar cells

Abstract

Small molecule organic dyes (SMODs) FWD7 and FWD8 featuring novel donor bis(arylvinyl)phenyl amino (BAPA) were designed for dye-sensitized solar cells (DSSCs). Absorption spectra of FWD7 featuring furanyl groups and FWD8 featuring thiophenyl groups showed about 20 nm bathochromic shifts and obviously bigger molar extinction coefficients (ε) compared with FWD5 featuring phenyl groups. The DSSCs sensitized by FWD7 and FWD8 exhibited good photovoltaic parameters: short-circuit current density (Jsc) 9.88 and 11.59 mA cm−2, open-circuit voltage (Voc) 0.69 and 0.75 V, and power conversion efficiency (η) 4.89% and 6.01%, respectively. The bigger Rrec and τe values of FWD8 (Rrec = 88.53 Ω cm−2 and τe = 10.76 ms) compared with FWD7 (Rrec = 59.06 Ω cm−2 and τe = 6.80 ms) gave a good explanation of the former’s bigger Voc. The results showed that both bis(furanylvinyl)phenyl amino and bis(thiophenylvinyl)phenyl amino groups are good donor groups, while the latter is more efficient.