High-performance near-infrared photodetector based on single-walled carbon nanotubes and PbS quantum dots

Because of the high carrier mobility and suitable bandgap of single-walled carbon nanotubes (SWCNTs), combining SWCNTs with bulk semiconductors to form heterostructures has become a promising approach for near-infrared (NIR) detection. In addition, lead sulfide quantum dots (PbS QDs), as zero-dimensional (0D) materials, exhibit excellent light absorption, easy preparation, and tunable bandgaps. Integrating PbS QDs on the surface of photodetectors can effectively enhance the optoelectronic performance. In this paper, a NIR photodetector with a PbS QDs/SWCNTs/InP structure is proposed. This device exhibits good optoelectronic performance. For the 808 nm wavelength, the responsivity and detectivity reach 486.7 mA/W at 1 V and 6.04 × 1011 Jones at 0.05 V, while for the 1064 nm wavelength, the responsivity and detectivity are 302.8 mA/W at 1 V and 1.12 × 1011 Jones at 0.05 V. Furthermore, the response time is good, with a rise time of 9 μs and a fall time of 55 μs. Wireless optical communication is achieved based on these excellent properties of the device. These results provide a method to enhance NIR detection.