Novel spiro-based hole transporting materials for efficient perovskite solar cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Organic-inorganic hybrid perovskite solar cells (PSCs) are a promising photovoltaic technology.
• Hole transporting materials (HTMs) are crucial components influencing PSC performance and stability.
• Spiro-OMeTAD is a widely used but often expensive HTM.

Purpose of the Study:

• To synthesize and evaluate novel spiro-acridine-fluorene based HTMs for PSCs.
• To compare the performance of these new HTMs against the commercial standard, spiro-OMeTAD.
• To investigate the properties of the most promising HTM candidate.

Main Methods:

• Fabrication of mesoscopic TiO2/CH3NH3PbI3/HTM devices using three novel HTMs (CW3, CW4, CW5).
• Performance characterization including power conversion efficiency (PCE) measurements.
• Detailed analysis of the best performing HTM (CW4) regarding conductivity, mobility, morphology, and stability.

Main Results:

• Three spiro-acridine-fluorene based HTMs (CW3, CW4, CW5) were successfully synthesized and incorporated into PSCs.
• The device utilizing CW4 achieved a maximum PCE of 16.56% with specific additives (tBp and Li-TFSI) and without cobalt doping.
• CW4 exhibited favorable conductivity, mobility, morphology, and stability characteristics.

Conclusions:

• Spiro-acridine-fluorene based HTMs, particularly CW4, show significant potential as efficient alternatives to spiro-OMeTAD in PSCs.
• The developed HTMs offer a promising route for cost-effective and high-performance perovskite solar cell fabrication.
• Further optimization and long-term stability studies of CW4 are warranted.