Flame Assisted Chemical Vapour Deposition of NiO hole transport layers for planar perovskite cells

Thin films of polycrystalline NiO were deposited by Flame Assisted Chemical Vapour Deposition, which is an ideal process for in-line, atmospheric pressure deposition of wide area coatings. This, along with the ability to use aqueous salts rather than organic precursors or solvents makes it well suited for industrial integration. To establish the capability of FACVD deposited NiO for use as a low cost, commercially viable option planar perovskite cells were fabricated under ambient conditions. The resulting cells showed the importance of both the flame composition and NiO thickness. A continuous NiO Hole Transport Layer (HTL) was achieved for ca. 36 nm thick film, which showed a maximum higher efficiency of 12.3% over that of the control (11.8%) which used a spin coated HTL. This was mainly driven by the large improvement in the current density from 16.6 mA/cm2 to 19.0 mA/cm2.