NANO.IL.

Conversion Process of PbS Thin Films to PbI2 and Subsequently to MAPbI3 Perovskite

Saar Peled Ilse Katz Institute for Nano-scale Science and Technology, Ben Gurion University of the Negev, Israel Department of Materials Engineering, Ben Gurion University of the Negev, Israel

Methylammonium lead halide perovskites (MAPbI3) are rapidly emerging as promising materials for high efficiency optoelectronic applications due to their large absorption coefficient over high spectral range, high charge carrier mobility, small exciton binding energies and long exciton diffusion length [1]. However, the stability and long term performances under operating conditions have been the main issues that need to be addressed before commercial perovskite based solar cells could be produced [2]. It has previously reported that there is a significant effect of the production process on the morphology and photovoltaic properties of the resultant perovskite [3]. This research show successful conversion of PbS thin films to PbI2 and afterwards to MAPbI3, and to study the effect of the conversion parameters on the perovskite films.

A two stage conversion process was preformed: first, PbS thin films with a columnar morphology with texturing along the (100) direction were immersed in polyiodide (iodine and potassium iodide) solutions, resulting in the formation of PbI2 films with different grain size. Columnar morphology of PbS films was chosen due to the fact that it has multiple grain boundaries, which make conversion process faster. Finally, the PbI2 films were immersed in a solution of methylammonium iodide (MAI) dissolved in isopropanol. This procedure resulted with two distinct grain sized perovskite films.

  1. Pradhan, J. et al. The Journal of Physical Chemistry C (2017).
  2. Jacobsson, T. J. et al. Inorganic chemistry 54.22 (2015): 10678-10685.
  3. Burschka, Julian, et al. Nature 499.7458 (2013): 316-319.








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