4. Conclusions
We developed a facile binder-free TiO2 paste based on commercially available formulation. Due to the dehydration of hydroxyl groups on the surface of TiO2 nanoparticles, the T-L paste works as “nanoglue” to interconnect nanoparticles. With the employment of PT paste, firm TiO2 film with high quality surface and excellent adhesion strength was obtained on the plastic conductive substrate (ITO/PEN) at room temperature. The photovoltaic performance of flexible DSSC is limited by the low electron transport and low light harvesting efficiency. CIP process was employed to replace the high temperature annealing to enhance the nanoparticle interconnection. With assistance from CIP method, thicker TiO2 film was fabricated on ITO/PEN to improve the light harvesting efficiency. Flexible DSSC module with parallel interconnection having dimension of 100 mm×100 mm was prepared by using PT paste. By using CIP process and increasing the TiO2 film thickness, flexible DSSC module with conversion efficiency of 3.27% was achieved. The efficiency with white background decoration was 3.61%. Flexible DSSC module with series interconnection was demonstrated to charge the mobile phone under indoor light. The results in this study show a promising future for the flexible DSSC module.