Van der Waals Integration of Bismuth Quantum Dots-Decorated Tellurium Nanotubes (Te@Bi) Heterojunctions and Plasma-Enhanced Optoelectronic Applications

Small. 2019 Nov;15(47):e1903233. doi: 10.1002/smll.201903233. Epub 2019 Oct 14.

Abstract

Van der Waals (vdW)-integrated heterojunctions have been widely investigated in optoelectronics due to their superior photoelectric conversion capability. In this work, 0D bismuth quantum dots (Bi QDs)-decorated 1D tellurium nanotubes (Te NTs) vdW heterojunctions (Te@Bi vdWHs) are constructed by a facile bottom-up assembly process. Transient absorption spectroscopy suggests that Te@Bi vdWH is a promising candidate for new-generation optoelectronic devices with fast response properties. The subsequent experiments and density functional theory calculations demonstrate the vdW interaction between Te NTs and Bi QDs, as well as the enhanced optoelectronic characteristics owing to the plasma effects at the interface between Te NTs and Bi QDs. Moreover, Te@Bi vdWHs-based photodetectors show significantly improved photoresponse behavior in the ultraviolet region compared to pristine Te NTs or Bi QDs-based photodetectors. The proposed integration of vdWHs is expected to pave the way for constructing new nanoscale heterodevices.

Keywords: bismuth quantum dots; heterojunctions; plasma; tellurium nanotubes; van der Waals.