Fig. 1. SEM and AFM images of FAPbBr₃ NS and CdS NBs. (a) SEM image of FAPbBr₃ nanosheet; (b) AFM image of a single FAPbBr₃ nanosheet; (c) SEM image of CdS NBs; (d) cross section of CdS NBs.

Fig. 2. XRD patterns of the samples: (a) CdS NBs; (b) FAPbBr₃ NSs.

Fig. 3. Spectral response of FAPbBr₃ NS/CdS NB hybrid structure. (a) UV-Vis absorption spectra; (b) (αhν)² versus photon energy curve of FAPbBr₃ NS; (c) and (d) spectral response of FAPbBr₃ NS device and FAPbBr₃ NS/CdS NB hybrid structures at a bias voltage of 5 V.

Fig. 4. (a) Schematic diagram of single FAPbBr₃ NS and (b) FAPbBr₃ NS/CdS NB hybrid structure device; (c), (d) SEM images of single FAPbBr₃ NS and FAPbBr₃ NS/CdS NB hybrid structure device, respectively; (e), (f) I-V curves of a single FAPbBr₃ NS device and FAPbBr₃ NS/CdS NB device under 490 nm light irradiation, respectively.

Fig. 5. Performance of FAPbBr₃ NS/CdS NB photodetector. (a) and (b) I-V curves; (c) and (d) photocurrent versus optical power density; (e), (f) EQE and (g), (h) D^* of single FAPbBr₃ NS device and CdS NB/FAPbBr₃ NS hybrid devices with increased light intensity under 490 nm laser at a bias voltage of 5 V.

Fig. 6. I–t characteristic curve of FAPbBr₃ NS/CdS NB photodetector. (a) Rising and falling edges of a single cycle with 5 V voltage offset; (b) photocurrent variation with time of CdS NB/FAPbBr₃ NS hybrid device; (c) photocurrent of the device.

Fig. 7. (a) Simulated electric field density distribution of different structures under light irradiation at 490 nm and (b) electric field distribution of a single FAPbBr₃; (c) and (d) electric field distributions of the FAPbBr₃/CdS hybrid device.

Table 1. Comparison of the Proposed Photodetector with Other Reported Devices in Terms of Photoresponse Parameters