Perovskite Precursor: High Quality Tin (II) Iodide (SnI₂)

In recent years, perovskite solar cells (PSCs) have received much attention as a novel solar cell type, and display power conversion efficiencies over 20% seen via PSC devices whose active layers were mainly consisted of lead.¹⁾ On the other hand, lead-free or mixed metal PSCs have also been heavily researched (Figure 1)²⁾ due to the concerns of lead toxicity. Tin is one of the possible lead alternatives, and tin(II) iodide can be readily used as a precursor of perovskites. Using a high quality precursor without contamination from tin(IV) compounds (e.g. SnI₄) is required in order to fabricate a good perovskite layer.³⁾ Subsequently, TCI offers product 1 as high quality tin(II) iodide for perovskite precursor with extremely low tin(IV) content to meet purity requirement needs. In addition, 1 is suitable for solution-processed solar cells because its water content is low (<100 ppm) and it provides clear DMF solutions (Figure 3).

Figure 1. A typical device structure of lead-free perovskite solar cells³⁾

Figure 2. Thermogravimetric (TG) analysis of 1

Figure 3. Crystalline solid (left) and DMF solution (right) of 1