Enhanced Photovoltaic Efficiency in Dye-Sensitized Solar Cells Using rGO/Cu²⁺:ZnO/Polymer (PMMA/PPy/PANI) Ternary...

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Dye-sensitized solar cells (DSSCs) are a promising renewable energy technology.
• Developing efficient and cost-effective photoanodes is crucial for DSSC performance.
• Zinc oxide (ZnO) and reduced graphene oxide (rGO) are explored for their electronic properties.

Purpose of the Study:

• To synthesize and characterize Cu²⁺-doped ZnO/rGO ternary nanocomposites for DSSC photoanodes.
• To investigate the effect of Cu²⁺ doping on the structural, optical, and electronic properties of ZnO/rGO.
• To evaluate the photovoltaic performance of these nanocomposites in DSSCs.

Main Methods:

• Oxalate-assisted wet-chemical precipitation for synthesizing Cu²⁺:ZnO/rGO.
• Electron microscopy (SEM) for morphology analysis.
• Photoluminescence spectroscopy for charge carrier recombination studies.
• Hall effect measurements for charge transport properties.
• Fabrication and testing of DSSCs with the synthesized photoanodes.

Main Results:

• Cu²⁺ doping narrowed the ZnO band gap, enhanced visible-light absorption, and suppressed charge recombination.
• Morphology evolved to hierarchical porous microspheres, preserving the ZnO wurtzite phase.
• Carrier mobility and electrical conductivity of ZnO/rGO significantly improved with Cu²⁺ doping.
• The optimized 5% Cu²⁺:ZnO/rGO photoanode achieved a power conversion efficiency (PCE) of 4.9%, outperforming pristine ZnO/rGO (3.1%).
• Hybridization with PANI further increased the PCE to 5.6%.

Conclusions:

• Cu²⁺-doped ZnO/rGO nanocomposites are effective photoanodes for DSSCs.
• The enhanced performance is due to band gap modulation, improved charge transport, and suppressed recombination.
• Ternary hybridization with polymers like PANI offers synergistic benefits for interfacial charge transport and stability.
• This strategy provides a pathway for developing efficient, low-cost, and Pt-free ZnO-based DSSC photoanodes.