Monolayer 2D quantum materials subjected to gamma irradiation in high-vacuum for nuclear and space applications

Abstract

The stability and reliability of emerging two-dimensional (2D) quantum materials subjected to harsh environments, such as high-energy radiation, are of high importance, particularly in the fields of space, defense, and energy applications. In this work, we explored the effects of gamma radiation on the structural and optical properties of monolayer WSe2 and WS2 crystals. Raman and photoluminescence spectroscopies were employed to study and probe radiation-induced changes to the samples after exposure to intense gamma radiation (from a 60Co source) in a high-vacuum environment (∼1 × 10−6 Torr) and with various exposure times to vary the total accumulated dosage (up to ∼56 Mrad). In general, very small changes in optical or vibrational properties were observed compared to pristine samples, suggesting noteworthy stability even for high dosages of gamma radiation. Moreover, we found that WSe2 monolayer samples exhibited higher tolerance to gamma radiation compared to WS2 samples. These findings highlight the inherent stability of these 2D quantum materials in harsh radioactive environments, which motivates further investigation of their optical, electrical, and structural properties and exploration for use in future space, energy, and defense applications.

γ-Ray irradiation-induced unprecedent optical, frictional and electrostatic performances on CVD-prepared monolayer WSe2

“…Clearly, the friction force and friction coefficient increased monotonically with the increase in the radiation dose. This is different from the previous report because g-irradiation causes the molecular impact movement in the sample chamber, which increases the number of cavities, yields a high density of selenium vacancies, 34 generates deep electron traps, 46 which can invoke as charged scattering centers, making uneven stress distribution of the surfaces. Fig.…”

“…The WSe 2 crystals do not donate electrons to ll the gamma-induced positive charges (i.e., electron traps) on the substrate surface; hence, the PL peaks at 750 nm do not shi with the irradiation dose. 34 This was made possible by the g-ray irradiation that introduced anion (Se) vacancies, which rendered the sample effectively an n-doped WSe 2 monolayer. The PL spectra suggest that the g-ray irradiation treatment is an effective approach allowing the control of the structural defects in monolayers.…”

“…Recently, Elafandi et al have investigated monolayer WSe 2 and WS 2 crystals subjected to gamma irradiation in high-vacuum. 34 They observed that WSe 2 exhibited great tolerance to radiation exposure as conrmed by optical imaging and spectroscopy (Raman and PL) characterization. In an ambient laboratory atmospheric environment, the presence of oxygen cannot be ignored.…”

Two-Dimensional-Material-Based Field-Effect Transistor Biosensor for Detecting COVID-19 Virus (SARS-CoV-2)

“…Field-effect transistors (FET) have been attractive options for designing rapid, sensitive, and selective biosensors that require a small number of test targets , for clinical diagnosis, on-site detection, and point-of-care testing. , For example, recently graphene-based FET biosensor has proven to be a rapid device for identifying SARS-CoV-2 spike protein with a limit of detection (LOD) of 1 fg/mL . Although graphene has high electron mobility, because of the graphene’s near-zero bandgap, the off-state current leakage in graphene-based biosensors might increase, resulting in false signals. , Beyond graphene, semiconducting two-dimensional (2D) transition metal dichalcogenides (TMDCs) have recently emerged as promising materials for biosensing among other applications − because of their promising optical, electrical, and mechanical properties. − TMDCs have exhibited relatively larger tunable bandgaps ranging from a few millielectron volts (meV) to a few electron volts (eV) depending on the 2D materials, , resulting in a reduced off-state current and better signal-to-noise ratios. Among the family of TMDCs, tungsten diselenide (WSe 2 ) with 1.67 eV bandgap , has shown the lowest detection limits and highest linear-regime sensitivities compared to, for example, molybdenum disulfide (MoS 2 ) for detecting streptavidin .…”

Gamma Radiation-Induced Oxidation, Doping, and Etching of Two-Dimensional MoS2 Crystals

“…However, the successful deployment of 2D TMDCs in such applications can only be achieved if these materials are resilient and durable upon exposure to high doses of ionizing radiation. 1 Our work addresses this important question by investigating the gamma-radiation-induced processes in MoS 2 crystals within the high-dose regime under ambient conditions.…”