In this talk, we will present assembly strategies for the construction in aqueous solution of hybrid nanostructures comprising inorganic semiconducting nanoparticles (CdS and PbS) grown on DNA-wrapped carbon nanotubes employed as templates. The organization of these hybrids in nanoscale devices, including ones employed for multiplexed photoinduced electrical response, will be discussed.

In particular, solution-processed multiplexed photoresponsive devices were fabricated from CdS-CNT and PbS-CNT nanohybrids,^[1] displaying a sensitivity to a broad range of illumination wavelengths (405,532, and 650 nm). DNA-CNT and CdS-DNA-CNT devices show a drop in the current while PbS-DNA-CNT’s current increases upon light illumination, indicating a difference in the operational mechanisms between the hybrids. Furthermore, the ON/OFF photoresponse of PbS-DNA-CNT is only 1 s as compared to 200 s for the other two nanohybrid devices.

The mechanisms of the different photoresponses were investigated by comparing the performance under an inert and air atmosphere, and gate dependence device analysis and transient absorption spectroscopy measurements were also conducted. The results revealed that photoinduced oxygen desorption is responsible for the slower photoresponse by DNA-CNT and CdS-DNA-CNT, while photoinduced charge transfer dominates the much faster response of PbS-DNA-CNT devices.^[1] The strategy developed is of general applicability for the bottom-up assembly of CNT-based nanohybrid optoelectronic systems and the fabrication of solution-processable multiplexed devices.

[1] Adv. Funct. Mater. 2021, 31, 2105719