Benefits of the Hydrophobic Surface for CH3NH3PbI3 Crystalline Growth Towards Highly Efficient Inverted Perovskite Solar Cells

Molecules. 2019 May 27;24(10):2027. doi: 10.3390/molecules24102027.

Abstract

In inverted perovskite solar cells (PSCs), high-quality perovskite film grown on hole-transporting material (HTM) with pinhole-free coverage and a large grain size is crucial for high efficiency. Here, we report on the growth of pinhole-free and large grain CH3NH3PbI3 crystals favored by a hydrophobic small molecular HTM, namely, 4,4'-Bis(4-(di-p-toyl)aminostyryl)biphenyl (TPASBP). The hydrophobic surface induced by TPASBP suppressed the density of the perovskite nuclei and heterogeneous nucleation, thus promoting the perovskite to grow into a dense and homogeneous film with a large grain size. The CH3NH3PbI3 deposited on the TPASBP exhibited better crystallization and a lower trap density than that on the hydrophilic surface of indium tin oxide (ITO), resulting in a significant reduction in carrier recombination. Combined with the efficient hole extraction ability of TPASBP, a high efficiency of 18.72% in the inverted PSCs fabricated on TPASBP was achieved.

Keywords: crystalline growth; hole-transporting material (HTM); hydrophobic surface; inverted perovskite solar cells (PSCs); small molecule.

MeSH terms

  • Calcium Compounds / chemistry*
  • Crystallization
  • Electricity
  • Hydrophobic and Hydrophilic Interactions
  • Iodides / chemistry*
  • Lead / chemistry*
  • Methylamines / chemistry*
  • Oxides / chemistry*
  • Solar Energy*
  • Spectrophotometry, Ultraviolet
  • Tin Compounds / chemistry
  • Titanium / chemistry*
  • X-Ray Diffraction

Substances

  • Calcium Compounds
  • Iodides
  • Methylamines
  • Oxides
  • Tin Compounds
  • perovskite
  • Lead
  • indium tin oxide
  • methylamine
  • Titanium