Efficiency difference between furan- and thiophene-based D-π-A dyes in DSSCs explained by theoretical calculations

Area of Science:

• Materials Science
• Photovoltaics
• Computational Chemistry

Background:

• Phenothiazine (PTZ) dyes are crucial for dye-sensitized solar cells (DSSCs).
• Optimizing π-bridges is key to enhancing DSSC performance.
• Understanding structure-property relationships is vital for efficient dye design.

Purpose of the Study:

• To investigate the impact of furan versus thiophene π-bridges on PTZ dye performance in DSSCs.
• To elucidate the theoretical underpinnings of observed differences in DSSC efficiency.
• To provide a computational basis for designing superior PTZ dyes for solar energy conversion.

Main Methods:

• Employed density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations.
• Analyzed electronic structure, light absorption, and charge transfer properties of two PTZ dyes.
• Compared dye performance based on π-bridge composition (furan vs. thiophene).

Main Results:

• The furan-containing dye (dye1) exhibited superior short-circuit photocurrent density compared to the thiophene analogue (dye2).
• Dye1 demonstrated a larger driving force and enhanced light-harvesting efficiency.
• Increased photo-injected electrons into TiO2 for dye1 resulted in higher open-circuit photovoltage.

Conclusions:

• Furan emerges as a highly effective π-bridge for boosting PTZ dye performance in DSSCs.
• The study provides theoretical evidence supporting furan's role in improving DSSC efficiency.
• Findings offer valuable insights for the rational design of next-generation DSSC materials.