Dry deposited single-walled carbon nanotubes co-assisted with copper redox mediator-based electrolytes for photo-stability of dye-sensitized solar cells

Abstract

Abstract

In this study, we investigate the use of cost-effective and commercial semi-transparent dry-deposited single-walled carbon nanotubes (SWCNTs) as counter electrodes (CE) in dye-sensitized solar cells (DSSCs) with copper redox-based electrolytes. Electrochemical impedance spectroscopy reveals a significant reduction in cell resistance (RCELL=36.15 Ω cm2, RCELL=103.30Ω), showcasing improved electrochemical activity compared to conventional platinum (Pt) catalyst layers (RCELL=52.17 Ω cm2, RCELL=149.04 Ω). Analyses indicate a 1.5 times larger electrochemical active surface area (ECSA) in dry-deposited SWCNTs-CE, emphasizing superior catalytic performance. These DSSCs with dry-deposited SWCNTs-CEs achieve photovoltaic performance comparable to Pt-CEs, with a champion device efficiency of 5.6 % under standard conditions and impressive power conversion efficiencies exceeding 9.5 % and 10 % at low light irradiance levels. A key innovation is the introduction of Maximum Power Point Tracking (MPPT) for DSSCs, conducted for the first time, providing a new dimension to the research. Moreover, a 650-hour long-term stability test under continuous light exposure demonstrates the potential of dry-deposited SWCNTs as promising alternative catalyst materials due to their high chemical compatibility. The study not only introduces a novel method for depositing commercial dry-deposited SWCNTs but also underscores the importance of further research to enhance the durability and reliability of DSSC devices.