Inhibition of charge recombination for enhanced dye-sensitized solar cells and self-powered UV sensors by surface modification

- The surface modification to inhibit charge recombination was utilized in photovoltaic devices.
- Inhibition of charge recombination can prolong electrode lifetime in photovoltaic devices.
- Enhanced DSSCs and self-powered UV sensors based on SnO2 photoelectrodes were obtained by TiO2 modification.

The surface modification to inhibit charge recombination was utilized in dye-sensitized solar cells (DSSCs) and self-powered ultraviolet (UV) sensors based on SnO2 hierarchical microspheres by TiO2 modification. For DSSCs with SnO2 photoelectrodes modified by TiO2, the power conversion efficiency (PCE) was improved from 1.40% to 4.15% under standard AM 1.5G illumination (100 mW/cm2). The electrochemical impedance spectroscopy and open-circuit voltage decay measurements indicated that the charge recombination was effectively inhibited, resulting in long electron lifetime. For UV sensors with SnO2 photoelectrodes modified by TiO2 layer, the self-powered property was more obvious, and the sensitivity and response time were enhanced from 91 to 6229 and 0.15 s to 0.055 s, respectively. The surface modification can engineer the interface energy to inhibit charge recombination, which is a desirable approach to improve the performance of photoelectric nanodevice.

Inhibition of charge recombination was utilized to prolong electrode lifetime in dye-sensitized solar cells (DSSCs) and self-powered UV sensors based on TiO2-modified SnO2 photoelectrodes. The electrochemical impedance spectroscopy and open-circuit voltage decay measurements indicated that the electron lifetime was significantly prolonged in DSSCs after TiO2 modification. And in self-powered UV sensors, the sensitivity and response time were enhanced.162