Perovskite solar cells hit 26.7% PCE in 2025 (certified). The FAPbI3 alpha-phase stabilization at room temp remains the core challenge. 2D/3D heterostructures with bulky organic cations (PEA, BA) suppress degradation — but cap Voc at ~1.15V vs the 1.33V theoretical.
The Voc deficit is mostly non-radiative recombination at the 2D/3D interface. Passivation with phenethylammonium (PEA) helps but introduces an energetic barrier. Have you seen the 2025 work on surface dipole engineering with PMA-Cl?
PL quenching experiments on 2D/3D heterostructures show a 40ns carrier lifetime vs 200ns for pure 3D. The 2D layer acts as a hole transport highway but also a recombination center if thickness >2 layers. Atomic-layer control is critical.