The most stable perovskite solar cells so far reported are prepared from perovskite fomulations using organic cations:
http://science.sciencemag.org/content/358/6364/739
However, the organic cations seems to be unstable
Article Stability of Organic Cations in Solution-Processed CH3NH3PbI...
Do we need to go inorganic to 25 years stable perovskite solar cells?
Dear Antonio,
welcome,
There is evidence in the literature that vacuum deposited perovskite solar cells have much higher stability than solution processed ones. Please refer to the paper in the link:Article Highly stabilized perovskite solar cell prepared using vacuu...
The organic part in the compound is necessary and very important for the outstanding photoabsorption ability of the perovskite material that the material has very high absorption coefficient and thereby needs only very thin layer of active material. This is a major issue of the perovslites.
Best wishes
Dear Abdelhalim,
many thanks for your answer.
I agree with your point on the deposition by vacuum to get more stable devices working in non-inert condition. Deposition by vacuum should give more compact, fewer pinholes, perovskite films, which are less permeable towards water ingress and thus more stable in air.
However, there still not evident if the organic is a major issue for the long-term stability in inert condition, i.e. no water and no oxygen.
all the best
Dear antonio,
Yes! The organic cation compound has an effect on the perovskite stability against several parameters like: Humidity, UV irradiation, high temperature …, because the substitution of the organic compound with an appropriate fraction of another organic cation, can contribute to the change in the structural properties i.e. toward a more stable structure. For example the case of the substitution in the organic compound (Formamidinium with Methylammonium) in the FAPbI3 perovskite leads to the increasing in the number of hydrogen bonds between the iodide ions and the hydrogen of the ammonium moiety in the cation, thereby the structure can be made more stable due to the difference in the dipole moment of MA and FA which are 2.3 Debye and 0.21 Debye respectively. More information, please refer to the following papers in these links:
Article Stabilization of the Trigonal High-Temperature Phase of Form...
Article Atomistic Origins of High-Performance in Hybrid Halide Perov...
Best regard !
In case of Organic-Inorganic perovskite materials, instability is caused by organic part because of unfavorable conditions (moisture, UV light, Oxygen, temperature etc). In the presence of moisture, perovskite breaks’ into MAI organic salt and lead iodide. MAI again decomposed in to methylamine and hydroiodic acid (HI). HI further decomposes with two different reasons, one is due to presence of Oxygen (O2), it breaks into iodide metal and water molecules and anther hand in presence of UV light HI simply breaks into iodide metal and hydrogen gas. Thus presence of moisture and oxygen perfectly degrades the perovskite compound. But this explanation is for humidity and UV lights but even in glove box perovskite material has no long life.
Article Stability of perovskite solar cells
this article may give you good information regrading your question.
Yes I think organic cation is an issue for perovskite stability while perovskite is exposed to light, moisture, high temperature or air. But the all inorganic perovskite will be lack of structural stability becuase the sizes of inorganjc cations are relatively smaller than organic cations...
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