(CH3NH3)2Pb(SCN)2I2: a more stable structural motif for hybrid halide photovoltaics?

DOI: 10.1021/acs.jpclett.5b02177
PMID: 26525942

Authors: Alex M. Ganose (University College London) , Christopher N. Savory (University College London) , David O. Scanlon (University College London; Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: The Journal Of Physical Chemistry Letters , VOL 6 (22) , PAGES 4594 - 4598

State: Published (Approved)
Published: November 2015

Abstract: 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– 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.

Journal Keywords: MAPI; MAPSI; hybrid halide perovskite solar cells; thiocyanate (SCN)

Diamond Keywords: Photovoltaics; Semiconductors

Subject Areas: Chemistry


Technical Areas:

Added On: 11/12/2015 12:07

Documents:
acs.jpclett.5b02177.pdf

Discipline Tags:

Earth Sciences & Environment Sustainable Energy Systems Energy Climate Change Physical Chemistry Energy Materials Materials Science Perovskites Metallurgy

Technical Tags: