Modulated charge injection in p-type dye-sensitized solar cells using fluorene-based light absorbers

Area of Science:

• Materials Science
• Photovoltaics
• Organic Chemistry

Background:

• Dye-sensitized solar cells (DSCs) are a promising photovoltaic technology.
• Developing efficient organic dyes is crucial for advancing p-type DSCs.
• Tuning molecular structure impacts dye performance and spectral properties.

Purpose of the Study:

• To design and synthesize novel arylamine-fluorene based organic dyes for p-type DSCs.
• To investigate the effect of structural modifications on dye spectral coverage and energy levels.
• To evaluate the photovoltaic performance and charge injection efficiency of the synthesized dyes.

Main Methods:

• Synthesis of three pull-push arylamine-fluorene based dyes (zzx-op1, zzx-op2, zzx-op3).
• Fabrication and testing of p-type DSCs using NiO nanoparticles and I(-)/I3(-) redox couple.
• Characterization using UV-Vis spectroscopy, DFT calculations, transient photovoltage decay, and electrochemical impedance spectroscopy.

Main Results:

• Dyes zzx-op1, zzx-op2, and zzx-op3 were successfully synthesized.
• Spectral coverage extended to 750 nm with structural modifications.
• zzx-op1 achieved a 0.184% energy conversion efficiency with high charge injection (90.3%).
• Increased spectral broadening in zzx-op2 and zzx-op3 correlated with decreased charge injection efficiency.

Conclusions:

• The synthesized organic dyes show potential for p-type DSC applications.
• Structural modifications can tune spectral properties but may impact charge injection efficiency.
• A trade-off exists between spectral broadening and electron injection driving force in p-type DSCs.