Transparent sculptured titania films for enhanced light absorption in thin-film Si solar cells

This study presents a description of the enhancement of light absorption in thin-film silicon (Si) solar cells by using sculptured titania (TiO2) films. We used an electron-beam evaporation system with a glancing angle deposition (GLAD) method to deposit porous TiO2 films on fluorine-doped SnO2 (FTO) substrates. The GLAD TiO2/FTO films were used as conductive electrodes in hydrogenated microcrystalline silicon (μc-Si:H) solar cells. Transmission electron microscopy revealed that the GLAD TiO2 films are composed of sculptured nano-pillars on an FTO surface, and this nanostructure provides a synergistic route for light scattering enhancement. The GLAD TiO2/FTO exhibited a 68% improvement of optical haze (at λ = 600 nm). The μc-Si:H solar cells consisting of the GLAD-nanostructured TiO2 resulted in a 5% improvement of short-circuit current (Jsc) and yielded a cell efficiency of 6.6%.