(CH3NH3)2Pb(SCN)2I2: A More Stable Structural Motif for Hybrid Halide Photovoltaics?

详细信息    查看全文

• 作者：Alex M. Ganose ; Christopher N. Savory ; David O. Scanlon
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2015
• 出版时间：November 19, 2015
• 年：2015
• 卷：6
• 期：22
• 页码：4594-4598
• 全文大小：397K
• ISSN：1948-7185

文摘

Hybrid halide perovskites have recently emerged as a highly efficient class of light absorbers; however, there are increasing concerns over their long-term stability. Recently, incorporation of SCN^{鈥?/sup> has been suggested as a novel route to improving stability without negatively impacting performance. Intriguingly, despite crystallizing in a 2D layered structure, (CH₃NH₃)₂Pb(SCN)₂I₂ (MAPSI) possesses an ideal band gap of 1.53 eV, close to that of the 3D connected champion hybrid perovskite absorber, CH₃NH₃PbI₃ (MAPI). Here, we identify, using hybrid density functional theory, the origin of the smaller than expected band gap of MAPSI through a detailed comparison with the electronic structure of MAPI. Furthermore, assessment of the MAPSI structure reveals that it is thermodynamically stable with respect to phase separation, a likely source of the increased stability reported in experiment.}