Yaoyao Xu's research while affiliated with East China University of Science and Technology and other places

Dye-sensitized solar cells (DSSCs) have shown significant potential for indoor and building integrated photovoltaic applications. Herein we present three new D-A-π-A organic sensitizers, XY1, XY2 and XY3, exhibiting high molar extinction coefficients and a broad absorption range. Molecular modifications of these dyes, featuring a benzothiadiazole (BTZ) auxillary acceptor, were achieved by introducing a thiophene heterocycle, as well as by shifting the position of BTZ on the conjugated bridge. The ensuing high molar absorption coefficients enable highly efficient thin-film solid-state dye-sensitized solar cells with only 1.3 μm mesoporous TiO2 layer. XY2 with a molar extinction coefficient of 6.66×104 M-1 cm-1 at 578 nm led to the best photovoltaic performance of 7.51%.

Three functionally separated donor-π-acceptor (D-π-A) sensitizers CP-I–III with a cyano group as the electron-accepting group and a pyridine as the anchoring group have been developed for dye-sensitized solar cells (DSSCs). Significantly, the Jsc of CP-II, which contains a benzo[1,2,5]thiadiazole moiety, is much higher than those of CP-I and CP-III, which contain quinoxaline and [1,2,5]thiadiazolo[3,4-c]pyridine groups, respectively. This is not only a result of the good photon absorption, but also effective intramolecular charge transfer. The conversion efficiency (η) for CP-II-based DSSCs is 4.02 %, which is far better than that of CP-I and CP-III. Also, the η value for CP-II is much higher than that for the reference dye P-II with pyridine as anchoring group.