Figure 1. Hybrid perovskite phototransistors.
(a) Schematic of the phototransistor with a channel of hybrid perovskite CH3NH3PbI3. (b) Ultraviolet–visible absorption of the 100-nm CH3NH3PbI3 film. The inset shows a direct bandgap of ∼1.53 eV. (c) X-ray diffraction spectrum of the CH3NH3PbI3 film. (d) Top-view SEM image of the perovskite film. Scale bar, 0.5 μm. (e) Tapping-mode AFM height image of the perovskite film. Scale bar, 1.0 μm. Inset: the corresponding three-dimensional topographic image.