Layered PtSe₂ for Sensing, Photonic, and (Opto‐)Electronic Applications

Abstract

An increasing enthusiasm for research into 2D nanostructures is driven by their exceptional mechanical, chemical, optical, and physical properties that arise from their atomically thin dimension. These properties make 2D nanostructures promising candidates for applications in the next generation of photonic, valleytronic, and (opto-)electronic devices. 2D black phosphorus, for instance, is a novel 2D material with a thickness-tunable bandgap and outstanding properties that have attracted tremendous interest. However, its commercial and industrial applications have been greatly hindered by its poor environmental stability. [1] Layered transition metal dichalcogenides (TMDs), such as MoS 2 , WS 2 , and MoSe 2 , have been experimentally demonstrated to possess thickness-dependent bandgaps and many other promising physical, chemical, and mechanical properties. However, the majority of these TMDs suffer from relatively low charge-carrier mobilities, rather large Schottky barriers when contacted with metals, complicated fabrication processes and a narrow spectral response mainly in the visible region. [2,3] As a result, even though the first report on the experimental isolation of graphene was 16 years ago, [4] and researchers worldwide have spent massive time and effort investigating 2D materials, thus far few have been effectively employed in industrial and commercial applications. Recently, layered PtSe 2 , a Group-10 TMD, has been demonstrated to be one of the most promising 2D materials for adoption by industries due to its unprecedented photonic, physical, and chemical properties along with lowtemperature synthesis methods, high charge-carrier mobilities and long-term air stability. [5-11] One of the important industrial advantages of PtSe 2 is the developed synthesis methods, some of which are compatible with modern silicon technologies. The studied methods to synthesize layered PtSe 2 include molecular-beam epitaxy (MBE), [7,12] chemical vapor deposition (CVD), [8,13] thermally assisted conversion (TAC), [14-20] chemical vapor transport (CVT), [5] plasma-assisted selenization (PAS), [21] microwave assisted synthesis (MAS), [22] mechanical exfoliation (ME), [13,23] the wet chemical (WC) method, [24,20] and so on. Both MBE and CVD are typically carried out at high temperature and can result in high-quality PtSe 2 monolayers. In contrast, wafer-scale and thickness-tunable layered PtSe 2 can be obtained using TAC Since the first experimental discovery of graphene 16 years ago, many other 2D layered nanomaterials have been reported. However, the majority of 2D nanostructures suffer from relatively complicated fabrication processes that have bottlenecked their development and their uptake by industry for practical applications. Here, the recent progress in sensing, photonic, and (opto-)electronic applications of PtSe 2 , a 2D layered material that is likely to be used in industries benefiting from its high air-stability and semiconductor-technology-compatible fabrication methods, is reviewed. The advantages and disad...

Correlating Nanocrystalline Structure with Electronic Properties in 2D Platinum Diselenide

“…For material batch 4, device fabrication was done on the growth substrates, which already were the same Si/SiO 2 (90 nm) substrates. Transfer length method (TLM) and six-port Hall bar structures were then fabricated using contact lithography and a CF 4 process. In the first lithography step, the self-aligned edge contacts [51] were fabricated by first etching the PtSe 2 under the contact pads and then sputtering Ni and Al, followed by a lift-off process.…”

Edge‐Orientation Dependent Nanoimaging of Mid‐Infrared Waveguide Modes in High‐Index PtSe2

“…[ 15 ] PtSe 2 has been perceived as one of the most promising materials for future nanoelectronics and nanophotonics due to its exceptional properties, especially the long‐term air stability, high charge‐carrier mobility, and unique thickness‐dependent semiconductor to semimetal phase transition. [ 16 ] However, its near‐field characterization has yet to be performed on it. In this work, we performed near‐field imaging on PtSe 2 flakes at the MIR window by employing the s‐SNOM.…”

Hybrid Devices by Selective and Conformal Deposition of PtSe2 at Low Temperatures

“…[27,28] The remarkable properties of PtSe 2 , leading to numerous potential applications have been recently reviewed. [29] In short, PtSe 2 which undergoes a semimetal to semiconductor transition when thinned to a few layers, [30,31] has shown to have high potential in transistors, [32] chemical sensing, [25] IR-photodetection, [33,34] and piezoresistive sensors. [12] However, sputtering and evaporation processes offer a lower degree of conformality compared to ALD, leaving the highly demanded 3D unattainable.…”