Hybrids organic-inorganic perovskite(HOP) solar cells have unequivocally the potential for being a new generation of solar panels with a lower cost and a greater efficiency than well-known silicon solar panels. Today, even if HOPs are seen as one of the best ways to overcome climate change, they still have drawbacks to overcome, such as limited stability, especially in humid conditions. The more stable 2D perovskites, a low-dimension subfamily of the HOP is a good candidate to protect the 3D HOP while keeping a good efficiency. The understanding of the interaction between the 2D and the 3D perovskite is crucial to push the HOP cell toward the next step. Finally MoS2 nano flakes where investigated. We revealed the entire free carrier dynamics which is crucial for its use as a buffer layer in highly efficient and stable solar cell.