Controlled interfacial electron dynamics in highly efficient Zn2 SnO4 -based dye-sensitized solar cells.

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Zinc tin oxide (ZSO) is a promising material for dye-sensitized solar cells (DSSCs) due to its wide bandgap, high optical transmittance, and electrical conductivity.
• Current ZSO-based DSSCs show poor performance, largely due to a lack of systematic performance enhancement strategies.
• Interfacial engineering of the photoanode is crucial for improving ZSO-based DSSC efficiency.

Purpose of the Study:

• To propose and evaluate general strategies for improving the performance of ZSO-based DSSCs.
• To investigate the impact of interfacial engineering on electron transfer and recombination.
• To demonstrate the feasibility of ZSO as a non-TiO2 alternative for highly efficient DSSCs.

Main Methods:

• Deposited a conformal ZSO thin film blocking layer at the fluorine-doped tin oxide-electrolyte interface using pulsed laser deposition.
• Engineered the surface of ZSO nanoparticles (NPs) to create an ultrathin ZnO shell layer.
• Compared the performance of ZSO-based DSSCs with TiO2-based counterparts.

Main Results:

• The ZSO blocking layer improved short-circuit photocurrent density by 22% by suppressing back-electron transfer.
• Surface modification with a ZnO shell layer enhanced open-circuit voltage by 9% and fill factor by 4% by reducing electron recombination.
• ZSO-based DSSCs demonstrated faster charge injection and electron transport than TiO2-based DSSCs.
• Achieved a 6% overall conversion efficiency for ZSO-based DSSCs, a significant result for a non-TiO2 material.

Conclusions:

• Interfacial engineering strategies effectively enhance the performance of ZSO-based DSSCs.
• ZSO exhibits superior charge dynamics compared to TiO2, making it suitable for highly efficient DSSCs.
• The proposed methods offer a viable pathway towards developing efficient and cost-effective non-TiO2 DSSCs.