Transition metal dichalcogenides (TMDs) (MX 2 , M = Mo or W, X = S, Se, or Te) have attracted intense interest for developing ultrascaled electronics and optoelectronics by virtue of their attractive 2D layered structures and unique physical properties that are absent in their bulk counterparts. [1][2][3][4][5] Monolayer semiconducting TMDs show sizable direct bandgaps, quantum confinement effects, large exciton binding energies and effective valley polarizations, which unveils widespread applications in field-effect transistors (FETs), photodetectors, light-emitting diodes, pumped lasers, solar cells, and valleytronic devices. [6][7][8][9][10] More excitingly, their 2D structures offer superior electrostatic controllability and exemptible short-channel effects, rendering TMDs promising candidates for future sub-10 nm complimentary metal-oxide-semiconductor (CMOS) devices. [5,11,12] The applications of exfoliated TMD flakes in building high-performance prototypes of electronics, photonics, and optoelectronics have already been demonstrated. [13][14][15][16] The exfoliated flakes, however, suffer from Monolayer MoTe 2 , with the narrowest direct bandgap of ≈1.1 eV among Mo-and W-based transition metal dichalcogenides, has attracted increasing attention as a promising candidate for applications in novel near-infrared electronics and optoelectronics. Realizing 2D lateral growth is an essential prerequisite for uniform thickness and property control over the large scale, while it is not successful yet. Here, layer-by-layer growth of 2 in. wafer-scale continuous monolayer 2H-MoTe 2 films on inert SiO 2 dielectrics by molecular beam epitaxy is reported. A single-step Mo-flux controlled nucleation and growth process is developed to suppress island growth. Atomically flat 2H-MoTe 2 with 100% monolayer coverage is successfully grown on inert 2 in. SiO 2 /Si wafer, which exhibits highly uniform in-plane structural continuity and excellent phonon-limited carrier transport behavior. The dynamics-controlled growth recipe is also extended to fabricate continuous monolayer 2H-MoTe 2 on atomic-layer-deposited Al 2 O 3 dielectric. With the breakthrough in growth of wafer-scale continuous 2H-MoTe 2 monolayers on device compatible dielectrics, batch fabrication of high-mobility monolayer 2H-MoTe 2 field-effect transistors and the three-level integration of vertically stacked monolayer 2H-MoTe 2 transistor arrays for 3D circuitry are successfully demonstrated. This work provides novel insights into the scalable synthesis of monolayer 2H-MoTe 2 films on universal substrates and paves the way for the ultimate miniaturization of electronics.

A rapid HPLC-UV method for the determination of three organic acids (neochlorogenic acid, chlorogenic acid, and cryptochlorogenic acid) in Polygoni Vivipari Rhizoma (PVR) by one marker was developed. The sample was prepared by effervescence-assisted matrix solid-phase dispersion (EA-MSPD). The separation of compounds was performed on a Poroshell column. The equal absorption wavelength was set as follows: 292 nm (0∼7 min) and 324 nm (7∼10 min). The analytical time including sample extraction and HPLC separation time was 12 min. The analytical method validation such as accuracy (recoveries 99.85%–106.29% and RSD < 2.9%), precision (RSD < 1.3%), reproducibility (RSD < 1.7%), and stability tests (RSD < 0.7% in 24 h) proved that the established HPLC method was suitable for determination of three organic acids in PVR. The contents of three analytes obtained by the external standard method with three markers and the equal absorption wavelength method with one marker were similar (RSD ≤ 2.0%). The developed method, which is rapid and reference compound saving, is an improved quality evaluation method of PVR.