Dynamically controllable polarity modulation of MoTe ₂ field-effect transistors through ultraviolet light and electrostatic activation

Abstract

Energy band engineering is of fundamental importance in nanoelectronics. Compared to chemical approaches such as doping and surface functionalization, electrical and optical methods provide greater flexibility that enables continuous, reversible, and in situ band tuning on electronic devices of various kinds. In this report, we demonstrate highly effective band modulation of MoTe2 field-effect transistors through the combination of electrostatic gating and ultraviolet light illumination. The scheme can achieve reversible doping modulation from deep n-type to deep p-type with ultrafast switching speed. The treatment also enables noticeable improvement in field-effect mobility by roughly 30 and 2 times for holes and electrons, respectively. The doping scheme also provides good spatial selectivity and allows the building of a photo diode on a single MoTe2 flake with excellent photo detection and photovoltaic performances. The findings provide an effective and generic doping approach for a wide variety of 2D materials.

Van der Waals Heterostructures with Tunable Tunneling Behavior Enabled by MoO3 Surface Functionalization

“…The pristine MoTe 2 device shows a typical hole‐dominated ambipolar transport behavior and the MoS 2 transistor exhibits electron transport characteristics, consistent with previous reports . The pristine transfer characteristics of vdWHs shows anti‐ambipolar transport behavior ascribed to the recombination of the free holes in MoTe 2 and the free electrons in MoS 2 , which further verifies the type II band alignment in this pristine heterostructure device . Detailed electrical measurements of the individual and vdWHs device are demonstrated in Figure S2 in the Supporting Information.…”

Ion Gel‐Gated Nonvolatile Formation of Lateral MoTe2 Diode for Self‐Powered Near‐Infrared Photodetection

“…A variety of functional devices, including photodetectors and light‐emitting diodes, have been hitherto constructed based on pn junctions defined by single or split‐gate structures. The recent introduction of float gate further enables nonvolatile ES modulation to MoTe 2 , extending its application for memories and optoelectronic logic . However, deliberate multilayer stacking is generally required for such purposes.…”

Interface-Induced WSe2 In-plane Homojunction for High-Performance Photodetection

“…In the architecture, part of WSe 2 channel is on the Si/SiO 2 substrate and the other part is on the h-BN flake. This scheme is common in floating/semi-floating gate memories, in which the h-BN is adopted as gate dielectric layer [30,31]. The charges stored on one side of h-BN layer can regulate the conductivity of the material on the other side.…”