In organic-inorganic hybrid solar cells, long term stability of perovskite materials restricted due to ion migration within perovskite layer. Severe ion diffusion occurs, when PSCs are exposed to thermal stress or external electric field, generating defects which function as non-radiative recombination sites at the grain boundaries. Some of the solutions are mentioned here e.g. incorporation of graphite carbon nitride/phenylethyl ammonium iodide into perovskite layer can suppress ion migration to improve long term stability of the PSCs. Now question arises, are there some other methods to mitigate the ion migration?
Dear Hasan,
Wlelcome,
I see that you make a systematic study about the perovskite solar cells by questions answers. At first i would like to wish you success.
As for the answer of the question, there are tow types of ion migrations in the perovskites; the intrinsic and the extrinsic according to the source of ions. If the source of ions is out side the perovskite materials it is extrinsic and if it its source from the perovskite material itselfit will be intrinsic.
There are two main factors controlling this process:
The activation energy required to produce the ions, and
The diffusion coefficient or mobility of the ions
The activation energy is the matter of the molecular construction of the materials and how far it could be split into ions. It is observed that the Cl- ions have less activation energy and much larger diffusion coefficient than MA+ ions.
Since the formation of ions is a material property it ma be more effective to suppress the ion mobility. It is so that the ions move along the vacant sites between the grains of the materials and so filling this vacancies will reduce very much their diffusion in the material and suppress their accumulation inside the material. One can use materials with as high as possible activation energy for the ion formation.
In fact you can fine in the literature some proposals to suppress the suppress the formation of ions and their diffusion in perovskites.
Best wishes
Dear Hasan,
Wlelcome,
I see that you make a systematic study about the perovskite solar cells by questions answers. At first i would like to wish you success.
As for the answer of the question, there are tow types of ion migrations in the perovskites; the intrinsic and the extrinsic according to the source of ions. If the source of ions is out side the perovskite materials it is extrinsic and if it its source from the perovskite material itselfit will be intrinsic.
There are two main factors controlling this process:
The activation energy required to produce the ions, and
The diffusion coefficient or mobility of the ions
The activation energy is the matter of the molecular construction of the materials and how far it could be split into ions. It is observed that the Cl- ions have less activation energy and much larger diffusion coefficient than MA+ ions.
Since the formation of ions is a material property it ma be more effective to suppress the ion mobility. It is so that the ions move along the vacant sites between the grains of the materials and so filling this vacancies will reduce very much their diffusion in the material and suppress their accumulation inside the material. One can use materials with as high as possible activation energy for the ion formation.
In fact you can fine in the literature some proposals to suppress the suppress the formation of ions and their diffusion in perovskites.
Best wishes
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