Tandem photovoltaic device combining a silicon-based sub-cell and a perovskite-based sub-cell comprising a P- or N-type material/perovskite composite layer

A tandem photovoltaic device, comprising, in this superimposition order:

• A/a silicon-based sub-cell A comprising at least:
• a substrate made of crystalline silicon;
• and
• at least one layer, distinct from said substrate, made of N- or P-doped amorphous or polycrystalline silicon;
• and B/a perovskite-based sub-cell B, comprising at least:
• a lower layer, said lower layer being a semi-conductor layer of the N type in the case of a NIP structure, or being of the P type in the case of a PIN structure, and
• a composite layer, arranged on and in direct contact with said lower layer, said composite layer comprising at least one perovskite material and at least one second material, said composite layer having a gradient of the at least one perovskite material/at least one second material mass ratio, decreasing in a direction from an interface between a first face of said composite layer and said lower layer towards a second face of said composite layer opposite said first face of said composite layer, the at least one second material being a semi-conductor of the P type in the case said lower layer is of the N type or the at least one second material being a semi-conductor of the N type in the case said lower layer is of the P-type,
• the perovskite-based sub-cell B having a planar structure.