Fig. 2: Morphology of the BP-modified MAPbI3 perovskite films.
From: 2D materials for conducting holes from grain boundaries in perovskite solar cells
a–d SEM images of the perovskite films without and with 1–3 coats of BP flakes. The scale bar is 500 nm. e Schematic diagram of the grain boundary (GB) area when the BP dispersion in IPA was spin coated on the perovskite films. f Schematic diagram of the GB area after the deposition of BP and spiro-OMeTAD. Holes can transfer from the GB to the BP flake and then transport along the flake to the hole transport material spiro-OMeTAD
