Application tailored photovoltaic devices and methods exploiting mixed cation perovskites

A method of forming a precursor comprising:

• dissolving a number of individual components in one or more organic solvents;
• and
• dissolving an additive with the number of individual components;
• wherein
• the precursor provides for a doped perovskite film when processed onto a substrate;
• the precursor is a double cation perovskite solution;
• the precursor allows formation of doped perovskite films in ambient conditions;
• and
• the perovskite film has the composition FAXCsYPb(I1-ZClZ) where X, Y and Z range from 0.00001 to 3 respectively.

A method of fabricating a photovoltaic device comprising:

• forming a lower conductive layer;
• forming an active layer upon the lower conductive layer which generates an electrical current in dependence upon optical illumination within a predetermined wavelength range illuminating the active layer;
• forming an upper conductive layer upon the active layer;
• establishing a series of first scribe lines to isolate a first plurality of regions where each first scribe line of the series of first scribe lines penetrates down through the lower conductive layer;
• establishing a series of second scribe lines to isolate a second plurality of regions where each second scribe line of the series of second scribe lines penetrates down through at least the active layer but not the lower conductive layer;
• and
• establishing a series of third scribe lines to isolate a third plurality of regions where each third scribe line of the series of third scribe lines penetrates down through the active layer and upper conductive layer.