Novel push-pull dyes with cyclic ring spacers (titanol, chromol, ferrol, nickelol, and zinkol): a DFT study for optoelectronic optimization in DSSCs

Area of Science:

• Materials Science
• Computational Chemistry
• Renewable Energy

Background:

• Investigates bimetallic Zn/M organometallic D-π-A dyes for dye-sensitized solar cells (DSSCs).
• Focuses on the impact of transition metals (Ti, Cr, Fe, Ni) on optoelectronic properties and photovoltaic performance.
• Evaluates dye stability under vacuum and tetrahydrofuran (THF) solvation.

Purpose of the Study:

• To computationally design and assess novel bimetallic organometallic D-π-A dyes for enhanced DSSC performance.
• To understand the role of different transition metals in modulating dye optoelectronic behavior.
• To explore the effects of solvation on dye properties and stability.

Main Methods:

• Employs density functional theory (DFT) and time-dependent DFT (TD-DFT) simulations.
• Optimizes ground state geometries using the B3LYP functional with appropriate basis sets (LanL2DZ for metals, 6-31++G(d,p) for non-metals).
• Utilizes CPCM and SMD models for solvation studies and CAM-B3LYP functional for excited state calculations.

Main Results:

• Chromium-based dye (Dye2) shows excellent visible-light absorption (λmax=570 nm, LHE=85%).
• Nickel-based dye (Dye4) exhibits redshifted absorption (λmax=609 nm) and longer excited-state lifetime (1.55 ns) beneficial for charge separation.
• THF solvation significantly enhances light absorption and stability, with bathochromic shifts up to 138 nm.

Conclusions:

• Co-sensitization of chromium (Dye2) and nickel (Dye4) dyes is recommended to broaden spectral response and improve power conversion efficiency.
• The study highlights the potential of earth-abundant transition metals for developing efficient and sustainable DSSCs.
• Findings provide a roadmap for designing next-generation solar cell materials by balancing optical properties and charge management.