Degradation of organometallic halide perovskite photovoltaic absorbers probed by Raman spectroscopy

0450949 - FZÚ 2016 US eng A - Abstract
Ledinský, Martin - Loeper, P. - Niesen, B. - Haug, F.J. - Holovský, Jakub - Moon, S.J. - Yum, J. H. - Nicolay, S. - Bailat, J. - De Wolf, S. - Fejfar, Antonín - Ballif, C.
Degradation of organometallic halide perovskite photovoltaic absorbers probed by Raman spectroscopy.
MRS Fall Meeting & Exhibit 2014. Boston: MRS, 2014.
[MRS Fall Meeting & Exhibit 2014. 30.11.2014-05.12.2014, Boston]
R&D Projects: GA ČR GA14-15357S; GA MŠMT(CZ) LM2011026
Institutional support: RVO:68378271
Keywords : Raman * perovskites * photovoltaics * degradation
Subject RIV: BM - Solid Matter Physics ; Magnetism

Perovskite solar cells are known to degrade at moderate temperatures and upon moisture ingress. Here, we present micro-Raman spectra of CH3NH3PbI3 perovskites films that reveal this phenomenon locally on the micrometer scale. Raman spectra of freshly prepared non-degraded CH3NH3PbI3 perovskites films were measured and the degradation process was observed by repeatedly measuring the Raman signal on the same spot of the sample. Great care was taken to reduce the impact of the laser light on the perovskite sample during the measurements as much as possible to ensure a well-controlled degradation. During the degradation process, Raman spectra are changing from pure CH3NH3PbI3 perovskites spectra to spectra that closely resemble those of PbI2 thin films. At the same time, the absorbance of the film locally changes and the film becomes more transparent at the excitation wavelength of 514 nm.
Permanent Link: http://hdl.handle.net/11104/0252139