Rutherford Backscattering Spectroscopy of Mass Transport by Transformation of PbI2 into CH3NH3PbI3 within np-TiO2
Journal article
Authors/Editors
Research Areas
Publication Details
Subtitle: Rutherford Backscattering Spectroscopy of Mass Transport by Transformation of PbI2 into CH3NH3PbI3 within np-TiO2
Publisher: The Japanese Explosives Society
Publication year: 2015
Volume number: 1
Issue number: 1
Start page: 52
End page: 61
Number of pages: 10
ISSN: 1347-9466
Languages: English-United States (EN-US)
Abstract
Mass transport during transformation of PbI2 infiltrated in nanoporous TiO2 into CH3NH3PbI3 has been investigated by Rutherford backscattering spectroscopy (RBS). Fast initial reaction kinetics were confirmed using optical ex-situ and in-situ measurements. Mapping with energy dispersive X-ray spectroscopy of the cross section of samples revealed a homogeneous PbI2infiltration in nanoporous TiO2 before transformation but an accumulation of Pb and I at the surface after transformation, in accordance with a depletion of Pb and I in a near surface region. Quantitative depth profiles of Pb and I were obtained from RBS analysis. An instant degradation of CH3NH3PbI3 to PbI2 and volatiles upon ion radiation was found. The concentration profiles ofPb could be simulated with a one dimensional diffusion model taking into account an effective diffusion coefficient of Pb in the nanocomposite (about 1.5⋅10-11 cm²/s) as well as a parameter considering frazzling at the surface due to formation of crystallites.
Keywords
CH3NH3PbI3, PbI2, nanoporous-TiO2, Rutherford backscattering spectroscopy (RBS), transport of lead, degradation
Documents
No matching items found.
