Wafer-Scale Black Arsenic–Phosphorus Thin-Film Synthesis Validated with Density Functional Perturbation Theory Predictions

Abstract

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.

2D V‐V Binary Materials: Status and Challenges

“…α‐AsP nanosheets have been synthesized on InP substrates in an MBE system . Although MBE technique is applied, the synthesis of α‐AsP nanosheets follows an atomic‐layer deposition growth mechanism due to the large lattice mismatch between AsP and substrates.…”

“…c) Cross‐section picture of the film. a–c) Reproduced with permission . Copyright 2016, American Chemical Society.…”

Highly Efficient Silicon Photonic Microheater Based on Black Arsenic–Phosphorus

“…It can help preventing the b‐AsP thin film from oxidization and keep the material stable over several months . Moreover, the large‐area synthesis technique of wafer‐scale b‐AsP films has been reported, which can enable the mass‐fabrication of the heater proposed in this work.…”

Two-Dimensional Materials in Large-Areas: Synthesis, Properties and Applications

“…Liquid exfoliation presents challenges in balancing produced quality vs largearea yield of 2D flakes. Agglomerations, limited-sized 2D sheets with arbitrary shapes and random distribution on substrates, have been drawbacks of liquid-phase exfoliation [73,74], Mechanical exfoliations, however, have been a benchmark for high-quality exfoliated 2D sheets, and innovative approaches have enhanced the lateral size and controllability in patterned transfer [20][21][22][23][24]. However, 1 3 bottom-up approaches, such as CVD, prevail as the most potent technique so far.…”

“…d Schematic of wafer-scale MBE grown 2D b-AsP achieved by evaporation of P 2 and As 2 followed by thermal annealing. Adapted with permission from the Ref [22]…”