Synthesis and characterization of hole transporting materials containing bis(carbazole) groups for solid-state dye-sensitized solar cells

• Published in: Molecular Crystals and Liquid Crystals Vol. 734; no. 1; pp. 118 - 128
• Main Authors: Jung, Suran, Kwon, Younghwan
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 11.02.2022; Taylor & Francis Ltd
• Subjects: bis(carbazole); Carbazoles; Chemical synthesis; DSSC; Dye-sensitized solar cells; Dyes; Electrochemical analysis; Electrochemistry; Energy levels; Ferric chloride; hole transporting material; Molecular orbitals; NMR; Nuclear magnetic resonance; Photoluminescence; Solar cells; Solid state; ssDSSC; Structural integrity; Transportation
• ISSN: 1542-1406; 1563-5287; 1527-1943
• DOI: 10.1080/15421406.2021.1972220

In this study, bis(carbazole) derivatives, such as bis[N-(2-ethylhexyl)-carbazole-3-yl] (HTM_I) and bis[N-(2-ethylhexyloxylphenyl)-carbazole-3-yl] (HTM_II), were successfully synthesized for use as small-molecule organic hole-transporting materials (HTMs) in solid-state dye-sensitized solar cells (ssDSSCs) by coupling two respective carbazole moieties using FeCl 3 catalyst. The structural integrity of two compounds was identified by 1 H and 13 NMR. Maximum UV-vis absorption and photoluminescence peaks were observed at 306 nm and 425 nm for HTM_I, and at 306 nm and 425 nm for HTM_II, respectively. From the optical and electrochemical characterization, bandgap, HOMO, and LUMO energy levels were measured to be 3.26 eV, −5.52 eV, and −2.26 eV for HTM_I, and 3.37 eV, −5.61 eV, and −2.24 eV for HTM_II. The ssDSSC fabricated with HTM_II doped with TBP, MPII, and LiTFSI showed the highest PEC of 2.54%, with J sc = 6.55 mA/cm 2 , V oc = 0.55 V, and FF = 0.70.