Tuning the electronic properties of bondings in monolayer MoS₂ through (Au, O) co-doping

Abstract

This paper presents a comparative investigation of the electronic properties of un-, Au-, (Au, O) co-doped monolayer MoS 2 to analysis the effect of oxygen element on the electronic properties of Au-S bonding, with the goal of improving the conductivity of Au-S bonding of monolayer MoS 2 nanodevice with electrode Au. ABSTRACT: Improving the electronic properties of Au-S bonding is the key to tuning the carrier transport of monolayer MoS 2 -based nanodevice. Here, we systemically investigate the electronic properties for Au-, O-, and (Au, O) co-doped monolayer MoS 2 to analysis the electronic properties of Au-S bondings by using first-principles density functional calculations. Three gap states induced by Au-S bondings are observed at the band gap in Au-doped and (Au, O) co-doped monolayer MoS 2 , which are n-type semiconductors. Moreover, the n-type barrier between the Fermi level of Au-and (Au, O) co-doped systems and the CBM of un-doped monolayer MoS 2 are 0.84 and 0.65 eV, respectively. In addition, low electron density and electron density difference are observed for Au-S bondings in Au-doped monolayer MoS 2 , suggesting weak covalent Au-S bondings with high resistance, which explains the observed low carrier mobility of monolayer MoS 2 device with Au electrode. Upon introducing O element into Au-doped monolayer MoS 2 , electron density and electron density difference of Au-S bondings in (Au, O) co-doped monolayer MoS 2 are increased to 0.58 and 0.15 eV/Å 3 , respectively, showing that the covalent Au-S bondings are strengthened, and their resistance and electron injection efficiency are further improved by dopant O element. Our findings may provide an effective way to improve the electronic properties of Au-S bondings in monolayer MoS 2 -based nanodevice with Au electrode. system is weak. Our findings provide an effective way to improve the electronic properties of Au-S bondings monolayer MoS 2 -based nanodevice with electrode Au. Effect of substrate temperature on the electrical characteristics of MoSex thin films and back-gated MoSex transistors. J.Alloy. Compd. 2015, 623, 209-212.

Heterostructure consists of monolayer MoS2 and arsenene with novel electronic and optical conductivity

“…23 When monolayer MoS 2 bonds to arsenene, a transition from the direct band gap to the indirect band gap occurs, as shown in Fig. 23 When monolayer MoS 2 bonds to arsenene, a transition from the direct band gap to the indirect band gap occurs, as shown in Fig.…”

“…The carrier effective masses are calculated using the nearly free electron models. 19,28 Moreover, the band gap edges of pristine monolayer MoS 2 and arsenene mainly consist of Mo 4d and As 4p orbitals, respectively. This suggests that the As-MoS 2 heterostructure show the isotropic chemical character, which is consistent with the aforementioned band structure analysis.…”

The Structure–Property Correlations in the Isomerism of Au21(SR)15 Nanoclusters by Density Functional Theory Study

“…It can be seen that the average charge of all Au atoms (Au T ) in Au 21 hcp is comparable to that of Au 21 fcc (0.070 vs. 0.072 eV). In both cases, the staple Au atoms are more positively charged than the core Au atoms, predominantly due to the presence of more Au‐S bonds and the stronger covalent bonding characters in staple motifs . However, the Au core in Au 21 hcp is more positively charged, while the Au stap is less positively charged compared to the related ones in Au 21 fcc (0.055 vs. 0.029; 0.100 vs. 0.112).…”

“…In both cases, the staple Au atoms are more positively charged than the core Au atoms, predominantly due to the presence of more Au-S bonds and the stronger covalent bonding characters in staple motifs. [60] However,t he Au core in Au 21 hcp is more positively charged,w hile the Au stap is less positivelyc harged compared to the related ones in Au 21 fcc (0.055 vs. 0.029;0 .100 vs. 0.112). In otherw ords, the atomic chargeo ft he core and staple Au atomsb ecomes more differentiated in Au 21 fcc .T his result is mainly caused by the distinct number of Au-S stap and Au-S bri bondsi nt his pair of isomerism.…”

Promising Approach for High-Performance MoS2 Nanodevice: Doping the BN Buffer Layer to Eliminate the Schottky Barriers

“…As a transition metal dichalcogenide semiconductor, monolayer MoS 2 has received considerable attentions due to its extraordinary electronic, optical, mechanical, and thermal properties, and so on. − Its sizable direct band gap of ∼1.78 eV and fascinating physical behavior near the band edges enable monolayer MoS 2 to be suitable for kinds of nanodevices, including electronic, optoelectronic, photovoltaic, photochemical, and spintronic nanodevices. − More importantly, the ultrathin thickness (∼7 Å) and dangling-bond-free properties provide excellent gate electrostatic controls to suppress short channel effects of field-effect transistors (FETs). , Moreover, the fabricated monolayer MoS 2 FETs have demonstrated some excellent properties, such as high on/off ratio of 10 8 , high photoresponsivity, and strong spin-polarization . Hence, MoS 2 FETs have been regarded as potential nanodevices in further.…”