Effect of N-Butyl-1H-Benzimidazole Additive and Anisole Solvent on Spiro-OMeTAD for Solid-State Dye-Sensitized Solar Cells
Year: 2026
Type: dissertation
Abstract: Solid-state dye-sensitized solar cells (ss-DSSCs) have emerged as promising photovoltaic devices for light-harvesting, particularly under indoor illumination conditions. However, the use of toxic solvents during device fabrication and severe interfacial charge recombination under low intensity light conditions remain major challenges for their practical applications. This study aims to develop a more environmentally friendly and high-performance ss-DSSC by employing a chlorine-free solvent and enhancing interfacial passivation. In this work, anisole was introduced as a green solvent to replace the conventionally used but highly toxic chlorobenzene (CB) in the deposition of Spiro-OMeTAD. In addition, the Lewis base N-butyl-1H-benzimidazole (NBB) was explored as an alternative to the commonly used volatile passivating additive 4-tert-butylpyridine (tBP). Using the novel photosensitizer YKP-88, the ss-DSSCs photoanodes were made and the device performances were evaluated under both standard 1 sun illumination (AM 1.5G) and indoor lighting conditions (LED-5000 K). As a result, low NBB concentration (0.5 vol %) in Spiro could be considered as optimal concentration for the best performing device under 1 sun illumination by achieving a favorable balance between defect passivation and charge transport characteristics. Conversely, a high NBB concentration of 2 vol % obtained a superior indoor performance due to the formation of an effective blocking layer that suppressed both leakage current and interfacial recombination. The optimized devices achieved power conversion efficiency (PCE) of 4.99 % under 1 sun illumination and an indoor efficiency of 12.35 % at 500 lux, demonstrating the excellent adaptability of the YKP-88 dye under different illumination conditions. Overall, the combined use of anisole as a green solvent, NBB as an effective passivating additive, and the versatile YKP-88 dye provides an environmentally benign and efficient strategy for enhancing the performance of ss-DSSCs. These findings highlight a promising pathway toward the development of sustainable next-generation photovoltaic devices for indoor energy-harvesting applications.
Author: Long, Wuyang
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7164621620