A seeding method to change primary particle of oriented attachment network titanium dioxide for dye-sensitized solar cells

• The seeding method was used to improve thermal stability and thermal stress.
• The OA S2 has high surface area, lower Rw and perfectly aligned lattice.
• A higher efficiency was achieved by OA S2 as compared with commercial JGC 18NRT.

In this paper, we use seeding methods to improve crystal thermal stability and thermal stress by oriented attachment (OA) particles as seeds. The OA S2 synthesized by repeating two times the seed process has pure anatase phase even if was calcined and high surface area (113.2 m2 g−1). Further, the lattice images of OA S2 obtains from oriented attachment mechanism showed perfect alignment in grain orientation and no grain boundary appears between the necking particles. The films of OA S2 after calcination at 500 °C is homogeneous without cavities over large area. The photovoltaic performance of dye-sensitized solar cells made of OA S2 exhibits higher JSC and FF than the devices made of JGC 18NRT. The reason for the higher JSC can be attributed to the high surface area and pure anatase phase. The OA S2 shows the lower Rw (charge transport resistance) than the JGC 18NRT. It is confirmed that the OA S2 film has the capability of higher electron transmission due to oriented attachment structure, so it displays low internal resistance and results in higher FF. A higher light-to-electricity power conversion efficiency of 6.10% is achieved by applying the OA S2 as compared with JGC 18NRT (5.85%).