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Herein we report the wafer-scale synthesis of thin-film black arsenic–phosphorus (b-AsP) alloys via two-step solid-source molecular beam deposition (MBD) and subsequent hermetic thermal annealing. We characterize our thin films with a variety of compositional and structural metrology techniques. X-ray photoelectron spectroscopy and energy dispersive spectroscopy determine compositions of As0.78P0.22 for our thin films, while X-ray reflectivity measurements indicate film thicknesses of 6–9 nm. High-resolution transmission electron spectroscopy images reveal a nanocrystalline morphology with orthorhombic b-AsP grains on the order of ∼5 nm. Raman scattering spectroscopy is employed to characterize the vibrational spectra of our thin films, and the results obtained are in agreement with previously reported b-AsP spectra. Evidence of uniform wafer-scale growth is substantiated by Raman mapping. We simulate crystal structure, band gaps, and Raman spectra from first-principles DFT-based computations and find excellent agreement with our experimental results. This work is the first demonstration of on-wafer synthesis of b-AsP. Our large-area growth technique enables the development of next-generation b-AsP devices for optoelectronic, digital, and radio frequency (RF) applications.

In this letter, low noise amplification at 0.67 THz is demonstrated for the first time. A packaged InP High Electron Mobility Transistor (HEMT) amplifier is reported to achieve a noise figure of 13 dB with an associated gain greater than 7 dB at 670 GHz using a high f MAX InP HEMT transistors in a 5 stage coplanar waveguide integrated circuit. A 10-stage version is also reported to reach a peak gain of 30 dB. These results indicate that InP HEMT integrated circuits can be useful at frequencies approaching a terahertz. Index Terms-Coplanar waveguide (CPW), high electron mobility transistor (HEMT), low noise amplifier (LNA), millimeter-wave (MM-Wave), monolithic microwave integrated circuit (MMIC), sub-millimeter wave.

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