Impact of Sn doping on methylammonium lead chloride perovskite: An experimental study

Isostructural series of CH3NH3Pb(1-x)SnxCl3 (x=0%, 0.5%, 2.5%, 10%, 20%, and 33%) perovskites are prepared by the solution processing method. The synthesized perovskites are investigated in terms of their structural, optoelectronic, morphological, elemental, and thermal properties. The improved crystallinity and enhanced absorption edge toward longer wavelength are observed due to the increased amount of tin (Sn) in the Pb site of CH3NH3PbCl3. The bandgap is reduced from 2.93eV to 2.83eV when one third atomic percentage (at.%) of Pb is replaced with Sn. Further, elemental analysis confirms the successful doping of Sn in the host perovskite without the presence of any impurity. The thermogravimetric study of the prepared samples shows that the thermal stability is improving up to 20at.% Sn doping, whereas the stability starts deteriorating for 33at.% doping. The obtained results reveal that less toxic, better crystallinity, enhanced optoelectronic properties can be achieved by partial doping of Sn in CH3NH3Pb(1-x)SnxCl3 perovskites. This work offers a new reference for exploring the use of Sn-doped CH3NH3PbCl3 perovskite materials in optoelectronic devices.