| 초록 |
Hole-transporting materials (HTMs) used in n-i-p-type perovskite solar cells (PSCs) should be processed using green solvents to enable environmental-friendly device fabrication as well as having suitable energy levels and high hole mobility (μh) without using dopants. But none of them has been reported by far due to the limited solubility of HTMs in green solvents. Here, we report on a green-solvent-processable HTM, an asymmetric D–A polymer (asy-PBTBDT) that shows excellent solubility even in the 2-methylanisole, also known as food additive. The new HTM accomplishes a high μh (1.13 × 10–3 cm2/(V·s)) even without dopants. HTM produced a powerful PSC with 18.3% efficiency (91% retention after 30 days without encapsulation under 50% – 75% relative humidity) without dopants; an efficiency of 20.0% was achieved with dopants. Thus, this is the first report on a green solvent-processable hole-transporting polymer that exhibits the highest efficiency reported so far for n-i-p devices. |
