Electrical control of spatial resolution in mixed-dimensional heterostructured photodetectors

Proc Natl Acad Sci U S A. 2019 Apr 2;116(14):6586-6593. doi: 10.1073/pnas.1817229116. Epub 2019 Mar 19.

Abstract

Low-dimensional nanomaterials, such as one-dimensional (1D) nanomaterials and layered 2D materials, have exhibited significance for their respective unique electronic and optoelectronic properties. Here we show that a mixed-dimensional heterostructure with building blocks from multiple dimensions will present a synergistic effect on photodetection. A carbon nanotube (CNT)-[Formula: see text]-graphene photodetector is representative on this issue. Its spatial resolution can be electrically switched between high-resolution mode (HRM) and low-resolution mode (LRM) revealed by scanning photocurrent microscopy (SPCM). The reconfigurable spatial resolution can be attributed to the asymmetric geometry and the gate-tunable Fermi levels of these low-dimensional materials. Significantly, an interference fringe with 334 nm in period was successfully discriminated by the device working at HRM, confirming the efficient electrical control. Electrical control of spatial resolution in CNT-[Formula: see text]-graphene devices reveals the potential of the mixed-dimensional architectures in future nanoelectronics and nano-optoelectronics.

Keywords: 2D materials; carbon nanotubes; electrical control; photodetectors; van der Waals heterostructures.

Publication types

  • Research Support, Non-U.S. Gov't