Nature-imitating optimized photoelectrochemical process in BiSe nanosheets-based photodetectors

In this study, BiSe nanosheets were obtained by exfoliating bulk BiSe in liquid phase, and the prepared BiSe nanosheets were used as photoanode to construct photoelectrochemical (PEC) photodetectors with high photoresponse performance. At a light intensity of 80 mW/cm² and a bias potential of 0.4 V, the photocurrent density reaches 0.089 μA/cm², which is about 2.5 times that of the bulk BiSe. Further, the photocurrent density increased from 0.089 μA/cm² to 0.18 μA/cm² after the addition of photosynthesis-inspired additives (ATP and NADPH) to the electrolyte, and the rise time decreased significantly from 1.76 s to 0.13 s. The decay time was also significantly reduced from 2.27 s to 0.18 s. The improvement of photoresponse performance is due to the synergistic effect of ATP and NADPH, which inhibits the photogenerated electron–hole pair recombination and promotes the PEC reaction. The successful preparation of this high-performance photodetector is mainly due to the fact that the liquid-phase exfoliation effectively increases the specific surface of BiSe, and the introduced ATP and NADPH further improve the circulation and utilization of the photogenic carrier to promote the PEC reaction. This study provides a reference for the further research of BiSe materials in the field of photodetection, and confirms the feasibility of improving the performance of photodetectors through the combination of liquid-phase exfoliation to change the morphology characteristics and photosynthesizing electrolyte additives.