Fig. 1. Schematic of the perovskite/GaAs-nanowire hybrid structure photodetector preparation process.

Fig. 2. (a) SEM image of as-grown GaAs NWs, (b) the perovskite surface, (c) the photodetector, and (d) the EDS elemental mapping images of the perovskite/GaAs hybrid structure photodetector.

Fig. 3. (a) Energy-band diagram of the perovskite/GaAs-nanowire hybrid structure. (b) The absorption spectra for the single GaAs nanowire, perovskite, and perovskite/GaAs-nanowire hybrid structure. The diagram with the change of energy band and depletion region width (c) before and (d) after spin coating perovskite.

Fig. 4. (a) The photocurrent of the single perovskite with different power intensities at 532 nm. (b) The dark current of the single GaAs nanowire and perovskite/GaAs-nanowire hybrid structure photodetectors. The photocurrent (c) at 375 nm and (d) at 532 nm with different power intensities of the single GaAs nanowire photodetector. The photocurrent (e) at 375 nm and (f) at 532 nm with different power intensities of the perovskite/GaAs-nanowire hybrid structure photodetector.

Fig. 5. (a) The photocurrent comparison of perovskite, GaAs, and perovskite/GaAs hybrid structure photodetectors. (b) The photocurrent comparison at 375 nm and 532 nm wavelength of the single GaAs nanowire and perovskite/GaAs-nanowire hybrid structure photodetectors with the inset of the single GaAs nanowire absorption spectrum. (c) The responsivity of the hybrid structure photodetectors at 375 nm and 532 nm. The responsivity comparison of the single GaAs nanowire and hybrid structure photodetectors at (d) 375 nm and (e) at 532 nm. (f) Detectivity of the hybrid structure photodetectors at 375 nm and 532 nm wavelength.

Fig. 6. (a) The response time of three complete cycles of the single GaAs nanowire photodetector at 532 nm wavelength with (b) the rise and (c) decay times. (d) The response time of three complete cycles of the perovskite/GaAs hybrid structure photodetector at 532 nm wavelength with (e) the rise and (f) decay times.