Performance improvement of CdS quantum dots sensitized TiO₂solar cells by introducing a dense TiO₂blocking layer

A dense TiO 2 electron blocking layer was introduced on a conducting glass in CdS quantum dots sensitized solar cells to investigate electron leakage into the electrolyte. A ferricyanide/ferrocyanide redox couple was employed, as a model electrolyte, possessing a high standard rate constant. The analysis of the I – V characteristics, using a one-diode model, revealed that an increase in this layer, up to 50 nm, significantly suppresses the electron leakage, enhancing the shunt resistance by a factor of 200. An energy conversion efficiency of 1.0% was attained on account of the improved open circuit voltage and fill factor.