Stability Enhancement of Perovskite-Based Indoor Photovoltaics with Pulsed Laser-Ablated 2D-Layered Nanomaterials

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