Photovoltaic Effects of Dye-Sensitized Solar Cells Using Double-Layered TiO 2 Photoelectrodes and Pyrazine-Based Photosensitizers

• Published in: ACS omega Vol. 8; no. 16; pp. 14699 - 14709
• Main Authors: Kim, Mi-Ra, Pham, Thanh Chung, Yang, Hyun-Seock, Park, Sung Heum, Yang, Seah, Park, Myeongkee, Lee, Sang Gil, Lee, Songyi
• Format: Journal Article
• Language: English
• Published: United States 25-04-2023
• ISSN: 2470-1343; 2470-1343
• DOI: 10.1021/acsomega.3c00707

In this study, to obtain high performances of the dye-sensitized solar cells using the optimal TiO
photoelectrode for the synthesized pyrazine-based organic photosensitizers, three types of TiO
photoelectrodes were fabricated and evaluated for comparison. The double-layered nanoporous TiO
photoelectrode (SPD type) consisted of a dispersed TiO
layer and a transparent TiO
layer. The single-layered nanoporous TiO
photoelectrodes (D type and SP type) consisted of a dispersed TiO
layer and a transparent TiO
layer, respectively. The surface area, pore volume, and crystalline structures of the three types of TiO
photoelectrodes were analyzed by Brunauer-Emmett-Teller method, field-emission scanning electron microscopy, and X-ray diffractometry to confirm their crystallinity and surface morphology. The structures of the three types of TiO
photoelectrode-adsorbed organic sensitizers were investigated using X-ray photoelectron spectroscopy. The photovoltaic performances of DSSC devices using three organic photosensitizers adsorbed onto the three types of TiO
photoelectrodes were investigated under a light intensity of 100 mW/cm
at AM 1.5. The DSSC device using double-layered SPD type TiO
photoelectrodes displayed 1.31∼2.64% efficiency, compared to single-layered SP type TiO
photoelectrodes (1.31∼2.50%) and D type TiO
photoelectrodes (0.90∼1.54%), using organic photosensitizers. The DSSC device using the SPD type TiO
photoelectrode and trifluoromethylbenzopyrazine (TPPF) as a photosensitizer showed the highest performances:
of 5.69 mA/cm
,
of 0.69 V,
of 0.67, and efficiency of 2.64%. The relationship between photovoltaic effects and interfacial resistance characteristics of DSSCs using the three organic photosensitizers adsorbed onto the three types of TiO
photoelectrodes could be interpreted from interfacial resistances according to frequency through impedance analysis.