Effective Light Scattering Building Block for Enhanced Photoelectrochemical Performances of Flexible Solar Cells

Abstract

Solar cells fabricated on flexible plastic substrates possess great potential towards commercialization standing on their light-weight, low-cost, low-tech fabrication, and flexibility to tolerant different outdoor/indoor application requirements. A lack of a suitable material with both effective light scattering and high surface adhesion properties that would allow the development of a mechanically stable light trapping top-coating layer through a low temperature process prevents today’s flexible plastic dye-sensitized solar cells (DSCs) to reach comparable high power conversion efficiency (PEC) towards commercialization. In the present work, submicron sized titania particles with intensive surface roughness were strategically synthesized using a combined sol-gel and thermolysis approach. When used as a light trapping layer in flexible DSCs, the ideal strong light scattering ability of such materials enabled dramatic enhancements on light harvesting and thus greatly contributed to the photocurrent performances. This led to a nearly 30% PEC enhancement when compared to the flexible DSCs using photoanodes made of nanoparticles with a similar film thickness.