Monolithic all-solid-state dye-sensitized solar cells

The high cost of electricity produced by solar cells compared with electricity from other energy sources inhibits a more widespread adoption of solar energy. Here, a low-cost monolithic all-solid-state dye-sensitized solar cell (DSSC) was developed with a mesoscopic carbon counter electrode (CE). Based on the design of a triple layer structure, the TiO2 working electrode layer, ZrO2 spacer layer and carbon counter electrode (CE) layer are constructed on a single conducting glass substrate by screen-printing. With a vacuum pore-filling technique, solid-state materials such as PEO/PVDF polymer composite, poly(3-hexylthiophene) (P3HT) and 2,2', 7,7'-tetrakis(N, N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) hole transport material (HTM) could effectively infiltrate the multilayer thick films to assemble all-solid-state devices. The high surface area and large pore volume favor the penetration of the solidstate electrolyte materials and could reduce the resistance of the interface between CE and solid-state electrolyte. Correspondingly, efficiency up to 3.23% was obtained with polymer composite electrolyte and the dye of N719. With the dye of D102, efficiencies of 3.11% and 3.45% were obtained for the HTMs of P3HT and spiro-OMeTAD based electrolytes. In addition, a mesoscopic methylammonium lead iodide (CH3NH3PbI3) perovskite/TiO2 heterojunction solar cell was developed based on the monolithic structure and showed an efficiency of up to 6.53%. This design for monolithic DSSC with a carbon CE presents a promising commercial application prospect for this photovoltaic technology.