Epitaxial growth of large area single-crystalline few-layer MoS2 with high space charge mobility of 192 cm2 V−1 s−1

Abstract

We report on the vapor-solid growth of single crystalline few-layer MoS2 films on (0001)-oriented sapphire with excellent structural and electrical properties over centimeter length scale. Highresolution X-ray diffraction scans indicated that the films had good out-of-plane ordering and epitaxial registry. A carrier density of ~2 x 10 11 cm -2 and a room temperature mobility of 192 cm 2 /Vs were extracted from space-charge limited transport regime in the films. The electron mobility was found to exhibit in-plane anisotropy with a ratio of ~ 1.8. Theoretical estimates of the temperature-dependent electron mobility including optical phonon, acoustic deformation potential and remote ionized impurity scattering were found to satisfactorily match the measured data. The synthesis approach reported here demonstrates the feasibility of device quality few-layer MoS2 films with excellent uniformity and high quality.

Highly crystalline MoS2 thin films grown by pulsed laser deposition

“…[6][7][8] However, to materialize the promise of these TMD materials, appropriate methods for large area growth must be developed. To that end, extensive efforts have been applied following different approaches such as intercalation assisted exfoliation, [9][10][11] micromechanical exfoliation using scotch tape, 12-15 liquid exfoliation, 16 hydrothermal synthesis, 17 thermolysis of single precursors, 18,19 chemical vapor deposition, 20 vapor solid epitaxy, 21 and physical vapor deposition. [22][23][24] Recently, vapor-solid grown MoS 2 has been shown to have excellent electronic quality.…”

“…[22][23][24] Recently, vapor-solid grown MoS 2 has been shown to have excellent electronic quality. 21 However, the lateral dimensions of films synthesized by these various methods have mostly been limited to the order of a few hundred microns.…”

Carrier dynamics and transient photobleaching in thin layers of black phosphorus

“…The direct bandgap in black phosphorus is dependent on the number of layers, ranging from about 0.3 eV in bulk (5 or more layers) [3] to about 2 eV for a single layer [4]. In contrast to other two-dimensional materials, where the mobility is commonly far below that of graphene [5,6,7], the mobility in black phosphorus can approach values on the order of 10,000 cm 2 V -1 s -1 [1]. The presence of a direct band gap along with the high carrier mobility makes black phosphorus an interesting candidate for fast field-effect transistors [8] and optoelectronic devices like photodetectors [9,10].…”

Layer-transferred MoS2/GaN PN diodes

“…The resulting films were single crystal and exhibited epitaxial registry with respect to the sapphire substrate. 20 P-type conductivity in MoS 2 was demonstrated by adding a thin layer of Nb to the Mo metal precursor. 21 More recently, heterojunction devices utilizing two dimensional (2D) and bulk, traditional "3D" semiconductors (SiC 22 , Si 23 , 24 , 25 ) have been explored.…”