Enhanced stability and efficiency of Sn containing perovskite solar cell with SnCl2 and SnI2 precursors

• Published in: Journal of materials science. Materials in electronics Vol. 29; no. 21; pp. 18144 - 18150
• Main Authors: Kumari, Nitu, Patel, Sanjaykumar R., Gohel, Jignasa V.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2018; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Efficiency; Energy conversion efficiency; Lead; Materials Science; Optical and Electronic Materials; Perovskites; Photovoltaic cells; Precursors; Solar cells; Stability; Tin; Tin chloride
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-018-9926-y

Presence of toxic Pb and device stability are the main issues with perovskite solar cell. For Pb replacement, most likely substitute is Sn, which is a metal of group 14 (like Pb). Thus, in the present study, the amount of Pb is reduced and replaced by Sn. To achieve the replacement, use of SnCl 2 is explored in addition to generally used precursor (SnI 2 ), as the source of Sn. Molar ratio of PbI 2 :SnCl 2 /SnI 2 is varied to get optimum performance of perovskite solar cell. Pt–FTO counter electrode is used in addition to spiro-MeTAD (as hole transport material). The power conversion efficiency of solar cells containing 2:2 molar ratio of PbI 2 :SnCl 2 was enhanced to 10.10%, and PbI 2 :/SnI 2 was enhanced to 10.61%. Without Sn addition (CH 3 NH 3 PbI 3 ) the efficiency was only 7.39%. The clear enhancement of 37% (SnCl 2 ) and 43% (SnI 2 ) is highly encouraging, as it leads to less toxic and highly efficient solar cells at the same time. In addition, the percentage loss in power conversion efficiency of device prepared with SnCl 2 (CH 3 NH 3 Pb 0.5 Sn 0.5 ICl 2 ) was also superior (10 days).