Fig. 3From: High-Hole-Mobility Metal–Organic Framework as Dopant-Free Hole Transport Layer for Perovskite Solar CellsMorphology characterization of Ni3(HITP)2 films with different thicknesses. SEM images of a Bare ITO-coated glass and b–e Ni3(HITP)2 films with 20 nm, 30 nm, 40 nm, 50 nm, respectively; f AFM image of Ni3(HITP)2 film of 30 nm thicknessBack to article page