Improving chemical vapor deposition graphene conductivity using molybdenum trioxide: An in-situ field effect transistor study

Abstract

By using in situ field effect transistor characterization integrated with molecular beam epitaxy technique, we demonstrate the strong surface transfer p-type doping effect of single layer chemical vapor deposition (CVD) graphene, through the surface functionalization of molybdenum trioxide (MoO3) layer. After doping, both the hole and electron mobility of CVD graphene are nearly retained, resulting in significant enhancement of graphene conductivity. With coating of 10 nm MoO3, the conductivity of CVD graphene can be increased by about 7 times, showing promising application for graphene based electronics and transparent, conducting, and flexible electrodes.

Surface Transfer Doping‐Induced, High‐Performance Graphene/Silicon Schottky Junction‐Based, Self‐Powered Photodetector

“…The J SC of MoO 3 doped Gr/Si device nearly retained after air exposure; while the V OC was increased from 0.18 to 0.21 V, which is further illustrated in the time dependent photoresponse of J SC and V OC before and after air exposure, as shown in Figure b,c. Although the vacuum deposited MoO 3 thin film shows a significant work function decrease after air exposure, thereby leading to its degraded p‐type doping effect on graphene or organic molecules, the V OC of modified Gr/Si device was still enhanced after air exposure, which probably originates from the influence of oxygen or water molecules penetrating into the MoO 3 /Gr interface . Similar photodetecting behavior of air exposed modified Gr/Si device was also observed under the irradiation of other wavelengths (Figure S5, Supporting Information).…”

“…The transition metal oxide molybdenum trioxide (MoO 3 ) has been widely utilized in organic electronics, owing to its high work function . Moreover, MoO 3 has shown dramatic surface transfer hole doping effect on various 2D materials, such as graphene and MoS 2 . In this work, we demonstrate a remarkable performance enhancement of Gr/Si self‐power photodetectors, via the in situ surface functionalization of MoO 3 overlayer on graphene.…”

Stability of graphene doping with MoO3 and I2

“…1, in agreement with previous reports. 37 We therefore note that as higher doping levels can be obtained in vacuum, there remains potential to develop techniques that further improve the air-exposed MoO 3 doping. To calculate the Fermi level position with respect to the Dirac cone, we measured the mobility of graphene.…”

Surface transfer doping induced effective modulation on ambipolar characteristics of few-layer black phosphorus

“…Surface transfer doping relies on the interfacial charge transfer without introducing significant defects into the lattice structure of the as-doped materials, thereby nearly reserving their fundamental transport properties 38 . Various organic and inorganic species have demonstrated excellent doping effects on 2D materials such as graphene and TMDs, among which caesium carbonate (Cs 2 CO 3 ) and molybdenum trioxide (MoO 3 ) have been used to effectively modify the doping level of MoS 2 and grapheme, respectively 32,33 . Furthermore, the contact doping on TMDs FETs, such as MoS 2 and WSe 2 , has been shown to remarkably enhance the device performance owing to the effective modulation of Schottky barrier formed at contact/ semiconductor interface 13,36 .…”

“…Chemical doping, as a simple and effective doping approach, has been widely utilized to manipulate the electronic properties of 2D materials as well as organic semiconductors 13,[32][33][34][35][36] . Compared with the electrostatic modulation via an external electrical field, chemical doping usually provides a stronger nonvolatile doping capability with the ease of device fabrication 37 .…”