Physical Chemistry Research

Enhancing DSSC Efficiency through Anchoring Group Engineering in D-A-π-A Sensitizers: A TD-DFT Investigation

Document Type : Regular Article

Authors

Jaouad Ouhrir 1
Yahya Mekaoui 2
Ikram Mennas 3
El Mostafa Benharaf 3
Souad Taja 2
Mohamed El Idrissi 3
Bouzid Manaut 2

1 Laboratory of Research in Physics & Engineering Sciences, Sultan Moulay Slimane University, Polydisciplinary Faculty, Beni Mellal, Morocco. Team of Chemical Processes and Applied Materials, Sultan Moulay Slimane University, Polydisciplinary Faculty, Beni Mellal, Morocco

2 Laboratory of Research in Physics & Engineering Sciences, Sultan Moulay Slimane University, Polydisciplinary Faculty, Beni Mellal, Morocco

3 Team of Chemical Processes and Applied Materials, Sultan Moulay Slimane University, Polydisciplinary Faculty, Beni Mellal, Morocco

https://doi.org/10.22036/pcr.2025.541704.2727
Abstract
This study is based on Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT) methods, using the CAM-B3LYP functional with the 6-31G(d,p) basis set, to investigate five D-A-π-A type organic dyes (COL1 to COL5) intended for dye-sensitized solar cells (DSSCs). Particular emphasis is placed on the influence of anchoring groups. The electronic properties, charge transfer mechanisms, and light absorption capabilities of the dyes were evaluated. Among the sensitizers studied, COL5, which incorporates a sulfur-rich heterocyclic anchoring group, stands out for its efficient intermolecular charge transfer, reduced excitation energy (narrow energy gap), and strong electronic coupling with the TiO_2 surface. In contrast, dyes such as COL2, which contain less effective anchoring groups, exhibit weaker interfacial interactions and wider energy gaps. The analysis of the balance between electron injection driving force and open-circuit voltage highlights the critical role of anchoring group design in optimizing photovoltaic performance. Additionally, calculations of reorganization energies and charge transfer dynamics confirm that electron-deficient anchoring groups contribute to minimizing energy losses. Overall, these findings offer valuable insights for the rational design of high-performance dyes, identifying COL5 as a promising candidate for experimental validation and device integration.

Graphical Abstract

Enhancing DSSC Efficiency through Anchoring Group Engineering in D-A-π-A Sensitizers: A TD-DFT Investigation

Keywords

D-A- ">&pi
-A organic sensitizers, DSSCs, TD-DFT, Photovoltaic performance, Open-circuit voltage, Electron injection, Reorganization energies

Subjects

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Physical Chemistry Research
Volume 13, Issue 4
Autumn 2025
Pages 767-781

  • Receive Date 16 August 2025
  • Revise Date 24 September 2025
  • Accept Date 12 October 2025