Improving the Efficiency of Gallium Telluride for Photocatalysis, Electrocatalysis, and Chemical Sensing through Defects Engineering and Interfacing with its Native Oxide
Abstract:Gallium telluride (GaTe) is a van der Waals semiconductor, currently adopted for photonic and optoelectronic devices. However, the rapid degradation of GaTe in air, promoted by Te vacancies, is detrimental for device applications. Here, it is demonstrate that the surface oxidation of GaTe can be unexpectedly exploited for expanding the breadth of applications of GaTe. Specifically, the formation of a nanoscale sub-stoichiometric wide-band-gap Ga 2 O 3 skin, promoted by Te vacancies, over narrow-band-gap GaTe x… Show more
“…Notably, at optimized higher temperatures, GaTe maintains its preferred monoclinic structure, although GaTe exhibits poor environmental stability. 44,45 Even then we could not see the additional peak of any oxide or other phases of GaTe such as Ga 2 O 3 or TeO 2 or Ga 2 Te 3 . 32,45,46 So, the absence of additional diffraction peaks from impurities serves as strong evidence of the high purity of the samples.…”
Gallium telluride thin films have emerged as a promising material for various electronic and optoelectronic applications due to their unique properties. In this study, we investigate the growth of nanometer-thick GaTe films on sapphire substrates using molecular beam epitaxy and explore the influence of the growth temperature on the structural, electronic, and optical properties of the films. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman measurements are employed to characterize the structural quality of the films, while spectroscopy ellipsometry provides insights into their electronic and optical behavior. Our findings demonstrate that a higher temperature (500 °C) is the optimized growth temperature, which significantly impacts the quality and properties of GaTe thin films, making it a critical parameter for optimizing their performance in electronic and optoelectronic devices.
“…Notably, at optimized higher temperatures, GaTe maintains its preferred monoclinic structure, although GaTe exhibits poor environmental stability. 44,45 Even then we could not see the additional peak of any oxide or other phases of GaTe such as Ga 2 O 3 or TeO 2 or Ga 2 Te 3 . 32,45,46 So, the absence of additional diffraction peaks from impurities serves as strong evidence of the high purity of the samples.…”
Gallium telluride thin films have emerged as a promising material for various electronic and optoelectronic applications due to their unique properties. In this study, we investigate the growth of nanometer-thick GaTe films on sapphire substrates using molecular beam epitaxy and explore the influence of the growth temperature on the structural, electronic, and optical properties of the films. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman measurements are employed to characterize the structural quality of the films, while spectroscopy ellipsometry provides insights into their electronic and optical behavior. Our findings demonstrate that a higher temperature (500 °C) is the optimized growth temperature, which significantly impacts the quality and properties of GaTe thin films, making it a critical parameter for optimizing their performance in electronic and optoelectronic devices.
“…Currently, 2D GaTe has two crystal structures: m-GaTe and h-GaTe, as shown in Figure a,b, respectively. The layer configuration of GaTe consists of a quadruple layer containing four atomic layers of Te–Ga–Ga–Te. , For h-GaTe, the Ga–Ga bonds are completely perpendicular to the layer plane with an atomic stacking sequence of ABBA, forming a hexagonal crystal structure . On the other hand, m-GaTe presents a twisted posture, with one-third of the Ga–Ga bond in the structure changing from an out-of-plane position to an in-plane position .…”
semiconductors have recently attracted considerable attention due to their promising applications in future integrated electronic and optoelectronic devices. Large-scale synthesis of high-quality 2D semiconductors is an increasingly essential requirement for practical applications, such as sensing, imaging, and communications. In this work, homogeneous 2D GaTe films on a centimeter scale are epitaxially grown on fluorphlogopite mica substrates by molecular beam epitaxy (MBE). The epitaxial GaTe thin films showed an atomically 2D layered lattice structure with a T phase, which has not been discovered in the GaTe geometric isomer. Furthermore, semiconducting behavior and high mobility above room temperature were found in T-GaTe epitaxial films, which are essential for application in semiconducting devices. The T-GaTe-based photodetectors demonstrated respectable photodetection performance with a responsivity of 13 mA/W and a fast response speed. By introducing monolayer graphene as the substrate, we successfully realized high-quality GaTe/graphene heterostructures. The performance has been significantly improved, such as the responsivity was enhanced more than 20 times. These results highlight a feasible scheme for exploring the crystal phase of 2D GaTe and realizing the controlled growth of GaTe films on large substrates, which could promote the development of broadband, high-performance, and large-scale photodetection applications.
“…Furthermore, it has been found that introducing QDs to the surface of 2D nanomaterials increases the number of activation sites in 2D materials. As a result, most of the researchers are trying to make ultrasensitive detectors by using such heterojunctions. , There are several articles based on innovative 2D semiconductors, and their heterostructure sensor has been reported in the last few years. − The research may have used a specific research design or methodology that has limitations. For example, the research may have relied on self-report measures, which could be subject to biases or may not fully capture the complexity of the phenomenon under investigation.…”
A highly
sensitive array of two-dimensional (2D) WSe2 nanosheets
integrated with zero-dimensional (0D) SnS quantum dots
was synthesized by combining liquid-phase exfoliation and wet chemical
synthesis methods. The characterization results of scanning electron
microscopy (SEM), transmission electron microscopy (TEM), and X-ray
diffraction (XRD) revealed the formation of WSe2/SnS heterostructures,
which enable a cyclic and reproducible high gas sensing response.
The role allocation of SnS on WSe2 was verified by using
density functional theory (DFT) calculations. The result indicates
that the top alignment of SnS and the bottom layer of WSe2 act as a gas adsorption layer and carrier conduction layer, respectively.
The charge interactions of the heterostructures were systematically
explored by monitoring changes in the transferred characteristics
at room temperature (27 °C) after introducing 25–100 ppb
NO2. The highest sensing response of WSe2/SnS
heterostructures toward the NO2 gas was found to be 1.08
at 25 ppb with a LOD of 10.6 ppb. The experimental and simulation
results revealed that the charge transfer across the active sites
increased after incorporating SnS in the WSe2. The sensing
results showed an abrupt and reliable gas response under periodic
NO2 gas injection unambiguously achieved by such heterostructures.
The sensor also exhibited satisfactory stability and accuracy in selectivity
and is not affected by humidity at room temperature. DFT calculations
were also used to explain the sensing mechanism and heterojunction
for such nanocomposites.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.