Perovskite photovoltaics offer advantages for low-cost, efficient-energy production. However, interfacial losses currently limit device performance and stability. In this issue of Chem, Sutanto et al. visualize the energetic landscape of novel 2D/3D perovskite heterojunctions and thereby demonstrate the potential of optimized 2D perovskite layers as transport layers for high-performance, stable perovskite photovoltaics.