Photovoltaic Effects of Dye-Sensitized Solar Cells Using Double-Layered TiO2 Photoelectrodes and Pyrazine-Based Photosensitizers

Mi-Ra Kim; Thanh Chung Pham; Hyun-Seock Yang; Sung Heum Park; Seah Yang; Myeongkee Park; Sang Gil Lee; Songyi Lee

doi:10.1021/acsomega.3c00707

Photovoltaic Effects of Dye-Sensitized Solar Cells Using Double-Layered TiO₂ Photoelectrodes and Pyrazine-Based Photosensitizers

ACS Omega. 2023 Apr 12;8(16):14699-14709. doi: 10.1021/acsomega.3c00707. eCollection 2023 Apr 25.

Authors

Mi-Ra Kim¹, Thanh Chung Pham^{2

3}, Hyun-Seock Yang⁴, Sung Heum Park⁴, Seah Yang², Myeongkee Park¹, Sang Gil Lee⁵, Songyi Lee^{1

2}

Affiliations

¹ Department of Chemistry, Pukyong National University, Busan 48513, Korea.
² Industry 4.0 Convergence Bionics Engineering, Pukyong National University, Busan 48513, Korea.
³ Vietnam Academy of Science and Technology, Institute for Tropical Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 1000, Vietnam.
⁴ Department of Physics, Pukyong National University, Busan 48513, Korea.
⁵ Department of Food Science and Nutrition, Pukyong National University, Busan 48513, Korea.

Abstract

In this study, to obtain high performances of the dye-sensitized solar cells using the optimal TiO₂ photoelectrode for the synthesized pyrazine-based organic photosensitizers, three types of TiO₂ photoelectrodes were fabricated and evaluated for comparison. The double-layered nanoporous TiO₂ photoelectrode (SPD type) consisted of a dispersed TiO₂ layer and a transparent TiO₂ layer. The single-layered nanoporous TiO₂ photoelectrodes (D type and SP type) consisted of a dispersed TiO₂ layer and a transparent TiO₂ layer, respectively. The surface area, pore volume, and crystalline structures of the three types of TiO₂ 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 TiO₂ 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 TiO₂ photoelectrodes were investigated under a light intensity of 100 mW/cm² at AM 1.5. The DSSC device using double-layered SPD type TiO₂ photoelectrodes displayed 1.31∼2.64% efficiency, compared to single-layered SP type TiO₂ photoelectrodes (1.31∼2.50%) and D type TiO₂ photoelectrodes (0.90∼1.54%), using organic photosensitizers. The DSSC device using the SPD type TiO₂ photoelectrode and trifluoromethylbenzopyrazine (TPPF) as a photosensitizer showed the highest performances: J _sc of 5.69 mA/cm², V _oc of 0.69 V, FF 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 TiO₂ photoelectrodes could be interpreted from interfacial resistances according to frequency through impedance analysis.