Stability Enhancement\nof Perovskite-Based Indoor Photovoltaics\nwith Pulsed Laser-Ablated 2D-Layered Nanomaterials

The primary challenge in organic–inorganic perovskite-based\nphotovoltaics (PVs) mainly lies in losses attributed to trap-assisted\nnonradiative recombination and charge inhibition at the interface\nbetween the perovskite absorbing layer and the charge transport layers,\nwhich significantly contributes to instability and low photoconversion\nefficiency (PCE) of the PV. Here, a strategy to overcome the instability\nproblem by incorporating a small quantity of pulsed laser-ablated\ntwo-dimensional (2D) layered material, bismuth titanate nanoparticles\n(BiT NPs) after postcrystallization of a mixed formamidinium (FA)\nand cesium (Cs)-based precursor solution is proposed. The properties\nof the devices obtained using this strategy are then compared to those\nof reference 3D as well as modified 3D, namely conventional 2D/3D\nheterostructures based on 2D organic octylammonium bromide (OABr).\nWhile the bilayered inorganic perovskite additive formed a 2D/3D bilayer\nat the interface, it also contributed significantly to the observed\nstable charge carrier dynamics, particularly in terms of the recombination\nrate across the interface. In contrast to the moderately stable characteristics\nobserved for the unencapsulated reference 3D and 2D OABr-passivated\ndevices, those based on pulsed laser-ablated BiT NPs showed excellent\ndurability over a period of 1000 h, despite the slight compromise\nin terms of the PCE.