High-performance self-powered photodetectors based on the carbon nanomaterial/GaAs vdW heterojunctions

With the advantages such as simple structure, simple process and easy interface control, the photoelectric devices based on carbon nanomaterial/bulk semiconductor van der Waals (vdW) heterojunctions can fully realize the ultrahigh carrier mobility of carbon nanomaterials and the excellent photoelectric properties of bulk semiconductors. Especially, the novel mixed-dimensional vdW heterojunctions can be prepared by controlling the diameter/chirality and Fermi level of single-walled carbon nanotubes (SWCNTs) to form atomic-level interfaces and match bandgaps with bulk semiconductors. Here, we reported a self-powered broadband photodetector based on the pn vdW heterojunctions by combining (6, 5)-enriched semi-conducting SWCNT film with n-type GaAs, and used graphene to reduce the probability of carrier recombination in SWCNT film and to promote the carrier transport. The experimental results suggest that the self-powered device exhibits high-sensitivity photoelectric response toward the incident photons in the 405 similar to 1064 nm range, and that the max photoelectric responsivity of 1.214 A/W and the specific detectivity of 2 x 10(12) Jones could be achieved at zero bias.