Microwave-assisted hydrothermal synthesis of Cu-doped TiO2 nanoparticles for efficient dye-sensitized solar cell with improved open-circuit voltage

An important reason for the underlying power conversion efficiency (PCE) of the dye sensitized solar cells (DSSCs) is the low open-circuit voltage (V-oc). Considerable efforts have been made to increase the V-oc of DSSCs by suppressing charge carrier recombination dynamics, co-sensitization, and other strategies. Herein, we report an enhancement of the V-oc by the incorporation of Cu into TiO2 microstructure via microwave-assisted hydrothermal synthesis. The prepared nanoparticles and the photoanodes were tested for their efficacy with various structural, optical, and electrical characterization tools. It was found that the incorporation of Cu2+ into TiO2 lattice raises its conduction band (CB) edge and shifted the Fermi level upwards, which contribute towards enhanced V-oc. A significant enhancement in V-oc from 0.714 to 0.781 V was observed by the Cu incorporation. An optimized 1 wt% Cu modified TiO2 DSSC has shown an efficiency of 6.94% with a high V-oc of 0.762 V.

Automated summary

The incorporation of Cu into TiO2 microstructure was found to enhance the V-oc of DSSCs, leading to an improvement in efficiency.