title: Naphtho[2,3-c][1,2,5]thiadiazole and 2H-Naphtho[2,3-d][1,2,3]triazole-Containing D-A-π-A Conjugated Organic Dyes for Dye-Sensitized Solar Cells.
abstract: Dipolar dyes comprising an arylamine as the electron donor, a cyanoacrylic acid as electron acceptor, and an electron deficient naphtho[2,3-c][1,2,5]thiadiazole (NTD) or naphtho[2,3-d][1,2,3]triazole (NTz) entity in the conjugated spacer, were developed and used as the sensitizers in dye-sensitized solar cells (DSSCs). The introduction of the NTD unit into the molecular frame distinctly narrows the HOMO/LUMO gap with electronic absorption extending to >650 nm. However, significant charge trapping and dye aggregation were found in these dyes. Under standard global AM 1.5 G illumination, the best cell photovoltaic performance achieved 6.37 and 7.53% (∼94% relative to N719-based standard cell) without and with chenodeoxycholic acid (CDCA) coadsorbent, respectively. Without CDCA, the NTz dyes have higher power conversion efficiency (7.23%) than NTD dyes due to less charge trapping, dye aggregation, and better dark current suppression.
authors.affiliation: Institute of Chemistry, Academia Sinica , 115 Nankang, Taipei, Taiwan.
authors.forename: Yung-Sheng
authors.initials: YS
authors.lastname: Yen
authors.affiliation: Institute of Chemistry, Academia Sinica , 115 Nankang, Taipei, Taiwan.
authors.forename: Jen-Shyang
authors.initials: JS
authors.lastname: Ni
authors.affiliation: Institute of Chemistry, Academia Sinica , 115 Nankang, Taipei, Taiwan.
authors.forename: Wei-I
authors.initials: WI
authors.lastname: Hung
authors.affiliation: Institute of Chemistry, Academia Sinica , 115 Nankang, Taipei, Taiwan.
authors.forename: Chih-Yu
authors.initials: CY
authors.lastname: Hsu
authors.affiliation: Institute of Chemistry, Academia Sinica , 115 Nankang, Taipei, Taiwan.
authors.forename: Hsien-Hsin
authors.initials: HH
authors.lastname: Chou
authors.affiliation: Institute of Chemistry, Academia Sinica , 115 Nankang, Taipei, Taiwan.
authors.forename: Jiann-T Suen
authors.initials: JT
authors.lastname: Lin
keywords: 2H-Naphtho[2,3-d][1,2,3]triazole; D−A−π−A; Naphtho[2,3-c][1,2,5]thiadiazole; dye-sensitized solar cells; organic sensitizer