Passivated perovskite crystallization and stability in organic-inorganic halide solar cells by doping a donor polymer

Photovoltaic performance of planar perovskite hybrid solar cells (pero-HSCs) has been improved by mixing CH(3)NH(3)PbIxCl(3-x) and an electron donor polymer [ N-9''-hepta-hecanyl- 2,7-carbazole-alt- 5,5-(4',7'-di-2-thienyl- 2',1',3'-benzothiadiaz-ole)] (PCDTBT). PCDTBT contains lone pairs of electrons due to the presence of S and N atoms, which could passivate the trap states of the perovskite layer and thus reduce the number of film defects. A Stonehenge-like structure could be formed by the interaction of CH(3)NH(3)PbIxCl(3-x) and PCDTBT, developing more ordered orientation crystallization and a high quality film morphology. The doped solar cells are characterized by their excellent photovoltaic properties and enhanced stability. When the doping concentration is 0.3 mg mL(-1), the fabricated solar cell device exhibits an outstanding power conversion efficiency (PCE) of 15.76%, which represents a significant improvement with respect to the magnitude of 16% obtained for the reference device.