Low-Cost TiS2 as Hole-Transport Material for Perovskite Solar Cells

A room-temperature low-cost TiS2 p-type contact material is applied for the first time as the hole-transporting material (HTM) in perovskite solar cells, with power conversion efficiencies surpassing 13.5%. Synthesized by a simple two-step hot-injection method, it presents a much lower price per m(2) than octakis(4-methoxyphenyl)-9,9'-spirospirobi[9H-fluorene]-2,2', 7,7'-tetramine (spiro-OMeTAD), 30 times lower in price ($0.046 for TiS2 and $1.36 for spiro-OMeTAD at 13.54% efficiency), standing out over most of the reported HTM alternatives.