Flexible, Stable, and Efficient Counter Electrode for Quantum-Dot-Sensitized Solar Cells Based on Carbon Nanotube Films

With the rapid development in information, communication, energy, medical care, and other fields, the demand for light, strong, flexible, and stable materials continues to grow. Carbon nanotube (CNT) films possess outstanding properties, such as flexibility, good tensile properties, low density, and high electrical conductivity, making them promising materials for a wide range of applications. This paper reports an effective strategy that combines stretching treatment, laser etching, and electron beam deposition to fabricate an iron-deposited CNT film, which can serve as a counter electrode (CE) of quantum-dot-sensitized solar cells. The study also investigates the influences of processing parameters, such as stretching ratio and iron-depositing thickness on the film’s stacking structure, electrical conductivity, and catalytic activity. Under optimized stretching ratios and depositing thicknesses, the catalytic activity of the reacted deposited layer and the high electrical conductivity of the flexible film basis can be fully utilized, allowing the photoelectric conversion efficiency (PCE) of the solar cells to reach approximately 4.58%. Additionally, the CE exhibits flexibility, light transmission, and good stability, with its primary properties remaining above 97% after nearly 50 days. Thus, this research provides innovative material options and development strategies for the development of electrode materials.