Urea and acetamide as alternative electrolyte additives for efficient and stable dye-sensitized solar cells

• Published in: Journal of the Australian Ceramic Society 2023-12, Vol.59 (5), p.1213-1220
• Main Authors: Nguyen, De, Ngo, Ha-Phuong Thi, Vo, Anh-Tho Ngoc, Nguyen, Phuong Tuyet
• Format: Article
• Language: English
• Subjects: Ceramics; Chemistry and Materials Science; Composites; Glass; Inorganic Chemistry; Materials Engineering; Materials Science; Natural Materials
• ISSN: 2510-1560; 2510-1579
• DOI: 10.1007/s41779-023-00930-7

Increasing demands for more sustainable dye-sensitized solar cells prompt the search for electrolyte additives with lower production cost and environmental impacts. In this study, we explored the use of urea and acetamide as affordable and less volatile alternatives to the commonly used additive 4- tert -butylpyridine. DSC devices with the popular additive, 4 -tert- butylpyridine (TBP) at 0.5 M, enhanced short-circuit current density value ( J SC ) up to 21.0 mA/cm 2 , which was greater than the figure for devices with the 0.25 M acetamide additive. Contrarily, urea at concentrations of 0.5 M and 0.25 M increased the open circuit potential value ( V OC ) to 701 mV and 698 mV, respectively, which were competitive with the TBP of 731 mV. The long-term stability of DSC devices was positively impacted by urea and acetamide. While the DSC devices that used urea and acetamide electrolyte raised the V OC values greatly and two electrolyte groups still maintained their photovoltaic performance well, the V OC value in the TBP group increased about 10–20 mV after 240 h of storage. In addition, electrochemical impedance spectroscopy showed that urea, especially at 0.25 M, more effectively suppressed electron recombination at the TiO 2 /dye/electrolyte interface than TBP did. The Warburg impedance additionally demonstrated that the electrolyte with acetamide’s redox couplings could diffuse more effectively. Therefore, acetamide and urea are suitable to replace the hazardous chemical TBP in the DSC’s electrolytes.