Perovskite Solar Cells and Modules Employing Facile Synthesis and Green-Solvent-Processable Organic Hole Transport Materials

Developing low-cost and green-solvent-processable organic hole transport materials (HTMs) is essential to accelerate the commercial application of perovskite solar cells (PSCs). Herein, we report two easily synthesized HTMs, D-C6 and D-OC6, based on a double-spiral core unit. Compared to D-C6 with alkyl side chains, the introduction of alkoxy side chains increases the polarity of the terminal molecule D-OC6, making it easier to purify without chromatography and to be processed with the green solvent 2-methoxytoluene (2-MA). More importantly, D-OC6 can chelate with lead and lithium ions, thus inhibiting ion migration and lead leakage. The PSCs containing 2-MA-processed D-OC6 achieve a champion efficiency of up to 24.80%, along with excellent ambient operating stability. Most importantly, we have driven D-OC6 to large-area applications and fabricated perovskite solar modules with an active area of 17.1 cm2, achieving an efficiency of 21.00%. This study provides a commercially manufacturable HTM option for PSCs.