Hall and field-effect mobilities in few layered p-WSe2 field-effect transistors.
Sci Rep
; 5: 8979, 2015 Mar 11.
Article
de En
| MEDLINE
| ID: mdl-25759288
ABSTRACT
Here, we present a temperature (T) dependent comparison between field-effect and Hall mobilities in field-effect transistors based on few-layered WSe2 exfoliated onto SiO2. Without dielectric engineering and beyond a T-dependent threshold gate-voltage, we observe maximum hole mobilities approaching 350â
cm(2)/Vs at T = 300â
K. The hole Hall mobility reaches a maximum value of 650â
cm(2)/Vs as T is lowered below ~150â
K, indicating that insofar WSe2-based field-effect transistors (FETs) display the largest Hall mobilities among the transition metal dichalcogenides. The gate capacitance, as extracted from the Hall-effect, reveals the presence of spurious charges in the channel, while the two-terminal sheet resistivity displays two-dimensional variable-range hopping behavior, indicating carrier localization induced by disorder at the interface between WSe2 and SiO2. We argue that improvements in the fabrication protocols as, for example, the use of a substrate free of dangling bonds are likely to produce WSe2-based FETs displaying higher room temperature mobilities, i.e. approaching those of p-doped Si, which would make it a suitable candidate for high performance opto-electronics.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Langue:
En
Journal:
Sci Rep
Année:
2015
Type de document:
Article
Pays d'affiliation:
États-Unis d'Amérique