Enabling room-temperature processed highly efficient and stable 2D Ruddlesden–Popper perovskite solar cells with eliminated hysteresis by synergistic exploitation of additives and solvents

In 2D RP perovskites, two competitive processes of NH 4 Cl and DMSO additions reach a delicate balance in dual-treated devices, which deliver a maximum PCE up to 13.41% with excellent air-stability and eliminated hysteresis.