Nanostructured surfaces

Influence of laser radiation on the degradation of films of organic-inorganic CH3NH3PbI2.98Cl0.02 perovskite

Torchyniuk P.V.1,Yukhymchuk V.O.2, Greshchuk O.M.2, Kobylianska S.D.1, Belous A.G..1

1 Solid State Chemistry Department, V. I. Vernadskii Institute of General and Inorganic Chemistry of the NAS of Ukraine, Palladina ave., 32/34, Kyiv - 03680, Ukraine.
Corresponding author e-mail: pasha.torchyniuk@gmail.com

2 V. E. Lashkaryov Institute of Semiconductor Physics of the NAS of Ukraine, Prospect Nauki, 45, Kyiv-03028, Ukraine.

Perovskite solar cells (PSCs) based on organic-inorganic halide perovskites have attracted significant research interest in the field of solar cells due to the combination of factors such a highly effective and relatively cheap elements for solar energy conversion based on them. Over the past few years the power conversion efficiency of PSCs has dramatically increased from ~ 10% in 2012 to  the 22.1% in 2018 [1]. However, despite of this progress, it is necessary to solve serious problems related to their long-term stability before they can be successfully used as commercial solar cells. It is known that humidity, oxygen and ultraviolet radiation occur to the degradation of hybrid perovskite materials.
It was shown previously, that the shape and particle size of the obtained CH3NH3PbI2.98Cl0.02 films strongly depend largely on the stoichiometric ratio of the starting reagents (PbI2:CH3NH3I) [2]. When the amount of CH3NH3I is increased the transformation to the round, and then to faceted particles is observed [2]. In this case, the properties of the material is changed [2]. However, detailed studies of the stability of these materials with different morphology were not carried out.
The aim of this work was the investigation of the effect of laser radiation on the degradation of perovskite films CH3NH3PbI2.98Cl0.02 with different morphology. The effects of laser radiation with a wavelength of 532 nm at room temperature on the degradation of perovskite films at different density of radiation power and radiation times has been occured. It was found that the most stable are films with the highest ratio of CH3NH3I to PbI2 (3:1), which have morphology with faceted particles. 

1. Yang W.S., Park B.-W., Jung E.H., Jeon N.J., Kim Y.C., Lee D.U. et al Iodide.management in formamidinium-lead-halide–based perovskite layers for efficient solar cells // Science – 2017. – V. 356, № 6345.– P.1376–1379 
2. V’yunov O. I., Belous A.G., Kobylianska S. D., Kovalenko L. L. Impedance Analysis of Thin Films of Organic-Inorganic Perovskites CH3NH3PbI3 with Control of Microstructure // Nanoscale Res Lett– 2018. – V. 19, Article 98.