Design of Ag@C@SnO2@TiO2 yolk-shell nanospheres with enhanced photoelectric properties for dye sensitized solar cells

• Ag@C@SnO2@TiO2 nanospheres (ACSTS) is synthesized via a facile water bath method.
• The ACSTS exhibit improved light absorption ability with sufficient dye loading.
• Prolonged electron lifetime (171.1 m) is due to reduced charge recombination.
• Several kinds of nanospheres with different structures are also investigated systematically.
• Upon using ACSTS, an enhanced efficiency of 8.62% is achieved.

The hierarchical Ag@C@SnO2@TiO2 nanospheres (ACSTS) have been successfully synthesized by deposition of SnO2 and TiO2 on the Ag@C templates layer by layer. The size of ACSTS is ca. 360 nm while the Ag@C cores have an average diameter of about 300 nm. The rough and porous shell structure consisting of SnO2 and TiO2 ensures a large specific surface area (115.5 m2 g−1). To demonstrate how such a unique structure might lead to more excellent photovoltaic property, several kinds of dye-sensitized solar cells (DSSCs) are also fabricated using different nanospheres based photoanodes. It is found that the ACSTS based DSSC exhibits an obvious improvement in cell performance. According to various technical characterization, the ACSTS can provide dual-functions of light absorption and charge transfer, hence resulting in an enhanced short-circuit photocurrent density of 18.68 mA cm−2 and a higher FF of 63% compared with other DSSCs. The ACSTS cell finally obtains a PCE of up to 8.62%, increasing by 70.4% and 10.2% than hollow TiO2 nanospheres and Ag@C@TiO2 nanospheres based cells, respectively. The improved photovoltaic properties of ACSTS cell can be mainly ascribed to the unique microstructure and the synergistic effect of the encapsulated Ag@C cores.

Figure optionsDownload as PowerPoint slide