Dear Muhammed,

What do you mean with double pervoskite?

Do you mean tandem solar cells from two pervoskite materials, one for absorbing the shorter wavelength radiation and the other absorbing the longer wave length radiation of the incident solar radiation. The theory of operation of such double junction cell is similar two any two junction tandem cells where the the two two subcells must be matched to maximize the conversion efficiency. The radiation must be divided such that every cell has the same shortcircuit current.

Such all pervoskite tandem cells are produced with a new technology such that the layer growth is columnar  and the columns are aligned in all pervoskite layers.

For more information follow the link:http://www.futurity.org/perovskite-solar-cells-silicon-1278632-2/

Dear sir 

Structure of my perovskite is AA'MM'O6 

 Dear Muhammed,

The double pervoskites are an alternative to the hybrid pervoskite containing toxic leads. Then they perform the same function of the single pervoskites as they have similar electrical and optical properties. In principles the pervoskites work as an absorber in the solar cells and light emitting in LEDs.

As an example of double pervodkite please follow the link:https://arxiv.org/ftp/arxiv/papers/1611/1611.05426.pdf

Best wishes

Thank you sir