Fluorination on cyclopentadithiophene-based hole-transport materials for high-performance perovskite solar cells.

A new class of fluorinated cyclopenta[2,1-b:3,4-b']dithiophene (CPDT)-based small molecules, namely YC-oF, YC-mF, and YC-H, are demonstrated as hole-transporting materials (HTMs) for high-performance perovskite solar cells (PSCs). PSCs employing YC-oF as the HTM delivered an excellent efficiency of 22.41% with encouraging long-term stability.

Toward Large-Area and Fully Solution-Sheared Perovskite Solar Cells.

The solution shearing technique was used to prepare the various layers involved in perovskite solar cells (PSCs), with a device structure of FTO/c-TiO2/mp-TiO2/CH3NH3PbI3/Spiro-OMeTAD/Ag, in an area as large as 6 × 10 cm2. The film morphology and thickness of each layer were optimized by varying respective shearing parameters. The fully solution-sheared PSCs exhibited a champion power conversion efficiency (PCE) of 15.89%. In comparison, the PSCs with only perovskite layer solution-sheared and other layers spin-coated showed a high PCE of 17.27%. These results demonstrate the potential of a simple, rapid, cost-effective, and scalable solution shearing process to fabricate large-area PSCs and modules.