Design Of Titania Photo Anode Materials And Their Performance In Dye Sensitized Solar Cell

Dye sensitized solar cell (DSSC) is a new type of photovoltaic device, owns the merit of highenergy conversion performance, low cost and eco-benigh manufacture process, has become one ofthe focus in fields of photovoltaics. As the working electrode of DSSC, photoanode is the heartcomponent determining the photovoltaic efficiency. The surface features, particle size and shape,structural stability, as well as porosity of photoelectrode materials are all imported factors directlyrelavant to the performance of DSSC. In this thesis, we mainly study the impact of TiO₂photoanode material on the performance of DSSCs. Through the enhancement in light-harvestingcapability of photoelectrode by light scattering effects, the improvement in transferring ofphoto-generated electron, prolonging in the lifetime of photo electrons, retardation inrecombination of photo generated electron hole pairs, improving the collection of photo electronsand reach the aim of high performance. The main contributions of this thesis are as follows:(1) Three different sized TiO₂spindles with high crystallinity were synthesized by a two-stepsolvothermal reaction with the aid of amine. The90nm TiO₂spindles has the best pefermancebecause of high crystallinity, which resulted in the short-circuit current density (J_sc) of13.2mAcm^-2, open-circuit voltage (V_oc) of0.74V, fill factor (ff) of0.53and the energy conversionefficiency (η) of5.21%.(2) Rutile phase hierarchical TiO₂microspheres were synthesized by facile hydrothermalreaction. The product has high light scattering effects, so it is suitable as photoanode materials.The photoanode with TiCl₄treatment achieved apparent enhanced performance,the finallyshort-circuit current density (J_sc) is4.22, open-circuit voltage (V_oc) is0.66, fill factor (ff) is0.65,nd the energy conversion efficiency (η) is1.88%.(3) Graphene is a zero band gap material with excellent electrical conductivity and hugesurface areas. GS-TiO₂composite is regarded as an ideal photoanode material in DSSCs. GS-TiO₂composite were synthesised by sol-gel and hydrothermal reaction. The composite TiO₂-0.03GOdemonstated the short-circuit current density (J_sc) of16.17mAcm^-2, open-circuit voltage (V_oc) ofo.76V, and fill factor (ff) of0.58, and the overall energy conversion efficiency (η) of7.15%.