La2O3-encapsulated SnO2 nanocrystallite-based photoanodes for enhanced DSSCs performance

Area of Science:

• Materials Science
• Nanotechnology
• Photovoltaics

Background:

• Tin dioxide (SnO2) is a promising semiconductor material for photoanodes.
• Developing efficient and stable photoanodes is crucial for advancing solar energy technologies.

Purpose of the Study:

• To synthesize SnO2 nanocrystallites for photoanode applications.
• To investigate the effect of lanthanum oxide (La2O3) encapsulation on SnO2 photoanode performance.
• To understand the mechanisms behind the observed efficiency improvements.

Main Methods:

• One-pot hydrothermal synthesis of SnO2 nanocrystallites using tin (IV) chloride and fructose.
• Structural and morphological characterization of SnO2.
• Fabrication of SnO2 photoanodes and their encapsulation with thin La2O3 layers.
• Performance evaluation using dye-sensitized solar cells (DSSCs) with N719 dye.
• Electrochemical analysis including Mott-Schottky and Tafel measurements.

Main Results:

• SnO2 nanocrystallites with tetragonal crystal structure and spherical morphology were successfully synthesized.
• La2O3 encapsulation significantly improved key photovoltaic parameters: short-circuit current density (8.30 to 13.70 mA cm(-2)), open-circuit voltage (0.40 to 0.46 V), and power conversion efficiency (1.66% to 3.0%).
• Mott-Schottky and Tafel measurements confirmed a negative shift in the SnO2 conduction band position due to La2O3.

Conclusions:

• La2O3 encapsulation effectively enhances the performance of SnO2-based photoanodes in dye-sensitized solar cells.
• The efficiency gains are attributed to increased dye loading, improved photoelectron transfer, and a favorable shift in the SnO2 conduction band edge.
• This work presents a viable strategy for developing high-performance SnO2 photoanodes for solar energy applications.