Dear Ershad, what do you mean with one-step fabrication method?
Multi layer structures such as the perovskite solar cells need multiple steps to fabricate it. Even every layer can be produced with a sequence of processes to satisfy certain requirement and properties of the layer. So, you question needs clarification!
I just asked for the perovskite layer ... for example we have two-step spin spin PbI2/CH3NH3I method ... But I need a formula for one step CH3NH3PbI3 method ...
Thank you Sir for the paper ... it has a great idea of using other layers such as LiF and C60 to increase the efficiency .... However, I need a recipe for direct perovskite solar cells not planar structure ... I had to noted this point in my first comment ...