Efficient homogeneous and isomorphic blocking layer – Skeleton rutile TiO₂ electron transfer structure for quantum dot sensitized solar cells

Blocking layer and transfer skeleton of the electron transfer layer are found to play a crucial role in devices efficiency improvement. We develop a homogeneous and isomorphic electron transfer structure of rutile TiO₂ by preferred orientation growth in a facile two-step hydrothermal synthesis. The aligned TiO₂ nanowire array skeleton (TS) about 2.47 μm long grew neatly over the isomorphic ultra-thin blocking layer (BL). Those homogeneous and isomorphic structures promote the charge injection and transfer capability by means of increased driving force by higher Fermi-level and decreased resistance, in which the cell photocurrent and PCE improve significantly. Of the cells with isomorphic transfer structure, the PCE is 2.87%, the short-circuit current (J_sc) is 6.74 mA/cm², open-circuit voltage (V_oc) is 0.91 V and fill factor (FF) is 38.4% under one sun illumination (100 mW/cm²).