Triethanolamine doped multilayer MoS₂ field effect transistors

Abstract

Chemical doping has been investigated as an alternative method of conventional ion implantation for two-dimensional materials. We herein report chemically doped multilayer molybdenum disulfide (MoS) field effect transistors (FETs) through n-type channel doping, wherein triethanolamine (TEOA) is used as an n-type dopant. As a result of the TEOA doping process, the electrical performances of multilayer MoS FETs were enhanced at room temperature. Extracted field effect mobility was estimated to be ∼30 cm V s after the surface doping process, which is 10 times higher than that of the pristine device. Subthreshold swing and contact resistance were also improved after the TEOA doping process. The enhancement of the subthreshold swing was demonstrated by using an independent FET model. Furthermore, we found that the doping level can be effectively controlled by the heat treatment method. These results demonstrate a promising material system that is easily controlled with high performance, while elucidating the underlying mechanism of improved electrical properties by the doping effect in a multilayered scheme.

Li Intercalation Effects on Interface Resistances of High‐Speed and Low‐Power WSe2 Field‐Effect Transistors

“…We modeled the R DS as a resistance formed by the contact resistance (R contact ) on the gold electrode (Au)/top surface of the WSe 2 interface and additional interlayer resistances (R int ) at each multilayers WSe 2 interlayer interface (Figure 2e). We extracted the R DS and R channel using the Y-function method (Note S1 and Figure S3, Supporting Information) [35][36][37][38][39] (Figure 2f). The total resistance (R total ) is the sum of R DS and R channel .…”

“…[41] For µ, we used low field-effect mobility (µ 0 ) for minimizing effect of filed effect and contact resistance. [35][36][37] This µ 0 of pristine and after-Li intercalation were extracted from the slope of the fitted linear line in Figure S3a, Supporting Information, [35][36][37][38][39] and were 2 cm 2 V −1 s −1 and 108 cm 2 V −1 s −1 , respectively. After Li intercalation, the 2D sheet doping concentration increased from 4.64 × 10 12 cm −2 to 4.9 × 10 12 cm −2 , which indicates enhancement of carrier concentration by about 2.6 × 10 11 cm −2 due to electron transfer from intercalated Li ions.…”

Oxide-mediated recovery of field-effect mobility in plasma-treated MoS 2

“…At 6 s, the sample shows a marked increase in S sub , indicating that it is less sensitive to variations in the gate field around the region where the FET conductive channel is formed. This is expected to occur if the now-doped few topmost layers of the device have an increased charge trap density ( 22 ), originating from the plasma treatment.…”

Multiple machine learning approach to characterize two-dimensional nanoelectronic devices via featurization of charge fluctuation

“…We employ this data processing algorithm for a number of ΔI(t) data obtained from various 2D material based FETs which have been fabricated and analyzed under various experimental conditions such as different gate dielectrics 11,13,34,35 , temperatures 11,34,36 , channel materials 10,11,13,34,35,[37][38][39] , chemical/electron beam doping 40,41 , and source/drain contact metals 11,34 (see Fig. 1b).…”