dc.description.abstract | The first part article is continued on the structure of benzimidazole, which is widely used in our laboratory, and applied as a central core. Compare with imidazole, benzimidazole is a greater Lewis base, larger π-conjugation, and higher environmental and thermal stability, which is suitable for applied as hole transporting materials. According to previous works, we used two triphenylamines as donors connected on meta or ortho position at benzimidazole. The device tests found that meta position has greater power conversion efficiencies than ortho position. In this study, we synthesized IZB and IZF, in which IZB does not consist of fluorine but IZF consists of fluorine. Lastly, we investigate the relationship between fluorine effects and hydrophobicity applied as hole-transporting material in inverted perovskite solar cells. We expect the fluorine effect will passivate the defects of perovskite and its hydrophobic will reduce perovskite layer degradation, and enhance its power conversion efficiencies.
The second part article is about designing and synthesizing
pyrimidin-4-amine compounds as a central core in donors to synthesize QA series. Referring to literature reports, pyrimidin-4-amine is an excellent coplanarity structure, electron-donating group, great hole mobility, and UV light
absorption. In this study, we applied a fused ring and methoxyl phenyl group in pyrimidin-4-amine to extend π-conjugation. After that, benzene and biphenyl were used as π-conjugated linkers, and donors were connected to synthesize QBA and QPA. Because of QPA had solubility problem, we used QBA to further studies in salt effects. Moreover, we added pyridine to QBA to become QBAP and designed quaternary salts QBAPS, and compare them. Lastly, we applied QA series as hole-transporting material in inverted perovskite solar cells and expect QA series bring a suitable energy level, good solubility, and excellent thermal stability. For salt effects, we expect that QBAPS can passivate grain vacancies via perovskite layer to prevent carriers recombination. | en_US |