Highly efficient dye-sensitized solar cell developed by using sheet like TiO_2 prepared by a novel route

摘要

A novel and facile route has been developed for preparing TiO_2 nanopowder with crystalline anatase phase. This titanium dioxide powder prepared by using diethylamine (DEA) as capping agent, (TiO_2)_(DEA), has been characterized for its crystalline structure, surface morphology, and optical property by XRD, SEM, and absorption spectrum respectively. SEM micrograph of (TiO_2)_(dea) nano-powder revealed sheet like structure, XRD showed the anatase crystalline form and absorption spectrum provided the optical band gap of the prepared material as E_g = 3.27 eV. This (TiO_2)_(DEA) nanopowder was used to prepare its thin film photoelectrode using doctor's blade method. The solar cell constructed with this semiconductor electrode sensitized by N719 provided short circuit photocurrent (J_(sc)) 7.28 mA cm~(-2), open circuit potential (V_(oc)) 750 mV, fill factor (FF) 0.74 and overall conversion efficiency (η) 4.0% under illumination with light of 100 mW cm"2 intensity. The maximum JPCE obtained with such cell was 50%. These significantly high values of cell parameters have proven that the method developed during present work provided a very good quality (TiO_2)_(dea) powder for its application in dye-sensitized solar cell (DSSC). For comparison sake, the TiO_2 powder was also prepared using ammonia, instead of DEA, as capping agent keeping all other experimental conditions identical. When this (TiO_2)_(am) powder was used as photoanode and sensitized by N719, the cell outputs achieved were J_(sc)= 6.20 mA cm~(-2), V_(oc) = 640 mV, FF = 0.72 and η = 2.86% under illumination with light of 100 mW cm~(-2) intensity. The maximum IPCE obtained with such cell was 42%. This has clearly established that the quality of (TiO_2)_(dea) was superior than (TiO_2)_(am) for its use as photoanode material in DSSC.