Enhancement in photoelectric performance of dye-sensitized solar cells with inverted pyramid structures based on nanoimprint lithography

Abstract

The sunlight incident on outdoor solar cells comes from all directions, and the surface reflectance of covered glass of solar cells increases with the sunlight incident angle. The above-mentioned factors together lead to the absorption loss and low utilization of incident photons. An antireflection (AR) layer with micro-/nano-structures provides an omnidirectional-antireflection characteristic because of a gradual refractive index, which is a practical approach for solving the existing problems and further improving the photoelectric conversion efficiency (PCE) of solar cells. Micrometer-sized inverted pyramid structured polydimethylsiloxane AR layers were fabricated on surfaces of dye-sensitized solar cells (DSSCs) by a cost-effective method—nanoimprint lithography. Results show that the AR layers significantly reduce the reflectance and improve the PCE of DSSCs at oblique incidence. Reflectance decreases by 5.6%–10.58%, and the PCE relatively increases by 5.83%–15.25% in the light incidence angle range of 20°–60°. Meanwhile, the AR layer exhibits a hydrophobic surface with a water contact angle of ∼98.1°, which increases by 40.2° compared with the DSSC without the AR layer, and it further provides self-cleaning potential. Moreover, nanoimprint lithography could be integrated with industrial roll-to-roll technology, which reduces the fabrication cost and possesses industrial application potential.