Peripheral substituent regulation of bias structured azulene-based hole transport materials for perovskite solar cells

Hole transport materials (HTMs) have an important impact on the improvement of perovskite solar cell (PSC) performance. So far, HTMs with symmetrical and unbiased molecular structures have been extensively studied. Azulene, which is composed of a seven-membered ring and a five-membered ring, has shown nice potential in organic field-effect transistors and organic photovoltaic cells. In this research, we synthesized four bias structured HTMs (Azu-diT, Azu-diF, Azu-2T6F and Azu-2F6T) based on 2,6-substituted azulene. Among them, the more bias structured HTMs showed better electronic properties, and peripheral substitution on the 6-position of azulene had a greater influence on the solubility and film formation property. After being applied in PSCs, a power conversion efficiency (PCE) up to 16.16% was obtained by Azu-2T6F. These results demonstrate the potential of azulene derivatives as a hole transport material and the impact of biased peripheral regulation. Hole transport materials (HTMs) have an important impact on the improvement of perovskite solar cell (PSC) performance.

Automated summary

Hole transport materials (HTMs) play a crucial role in improving the performance of perovskite solar cells (PSCs). In this study, four biased structured HTMs based on 2,6-substituted azulene were synthesized and evaluated. The HTMs with more bias structure exhibited better electronic properties, and peripheral substitution on the 6-position of azulene had a significant impact on solubility and film formation. The highest power conversion efficiency (PCE) of 16.16% was achieved by Azu-2T6F when applied in PSCs.