Bulk photovoltaic effect (BPVE), featuring polarization-dependent uniform photoresponse at zero external bias, holds potential for exceeding the Shockley-Queisser limit in the efficiency of existing ...opto-electronic devices. However, the implementation of BPVE has been limited to the naturally existing materials with broken inversion symmetry, such as ferroelectrics, which suffer low efficiencies. Here, we propose metasurface-mediated graphene photodetectors with cascaded polarization-sensitive photoresponse under uniform illumination, mimicking an artificial BPVE. With the assistance of non-centrosymmetric metallic nanoantennas, the hot photocarriers in graphene gain a momentum upon their excitation and form a shift current which is nonlocal and directional. Thereafter, we demonstrate zero-bias uncooled mid-infrared photodetectors with three orders higher responsivity than conventional BPVE and a noise equivalent power of 0.12 nW Hz
. Besides, we observe a vectorial photoresponse which allows us to detect the polarization angle of incident light with a single device. Our strategy opens up alternative possibilities for scalable, low-cost, multifunctional infrared photodetectors.
This work investigates the resistive switching in InGaZnO (IGZO) memristors with different electrodes, including Cu, Au, Ag, and Ti. Cu electrode device possesses the lowest switching voltage, while ...Au electrode device exhibits a good endurance of 100 repeated cycling tests. Ag electrode device shows a mediocre performance. As for the Ti electrode device, it has a relatively larger on/off ratio but a highest switching voltage. Corresponding mechanisms for the current conduction are explored, and models based on the experimental results are proposed to explain the RS mechanisms. Additionally, multi-value storage potential of Cu electrode device is also investigated by varying compliance current.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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•Electronic and optoelectronic properties of vdW heterostructures are summarized.•Methods for preparing 2D vdW heterostructures is summarized in detail.•Optoelectronic applications of ...2D vdW heterostructures are highlighted.•Challenges and opportunities for 2D vdW heterostructures in optoelectronics are discussed.
Over the past decade, van der Waals (vdW) heterostructures has offered considerable freedom to integrate various two dimensional (2D) layered materials and proved themselves extremely versatile with unprecedented characteristics, unique functionalities and novel physics. Significant efforts have been contributed to the preparation, basic understanding, and applications of vdW heterostructures in the fields of electronics and optoelectronics. Herein, we review the recent advances of vdW heterostructures, such as, mechanical assembly of 2D vdW heterojunctions, direct vdW heterostructure growth, and the progress made in light-emitting diodes, photo detectors and photovoltaics. Finally, we conclude this review by discussing the current challenges facing 2D vdW heterostructures-based optoelectronics and offering our insights on future directions of this field.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Tremendous efforts have been devoted to preparing the ultrathin two‐dimensional (2D) transition‐metal dichalcogenides (TMDCs) and TMDCs‐based heterojunctions owing to their unique properties and ...great potential applications in next generation electronics and optoelectronics over the past decade. However, to fulfill the demands for practical applications, the batch production of 2D TMDCs with high quality and large area at the mild conditions is still a challenge. This feature article reviews the state‐of‐the‐art research progresses that focus on the preparation and the applications in electronics and optoelectronics of 2D TMDCs and their van der Waals heterojunctions. First, the preparation methods including chemical and physical vapor deposition growth are comprehensively outlined. Then, recent progress on the application of fabricated 2D TMDCs‐based materials is revealed with particular attention to electronic (eg, field effect transistors and logic circuits) and optoelectronic (eg, photodetectors, photovoltaics, and light emitting diodes) devices. Finally, the challenges and future prospects are considered based on the current advance of 2D TMDCs and related heterojunctions.
This feature article reviews the state‐of‐the‐art research progresses that focus on the preparation and the applications in electronics and optoelectronics of two‐dimensional (2D) transition‐metal dichalcogenides (TMDCs) and their van der Waals heterojunctions. First, the preparation methods including chemical and physical vapor deposition growth are comprehensively outlined. Then, recent progress on the application of fabricated 2D TMDCs‐based materials is revealed with particular attention to electronic (eg, field effect transistors and logic circuits) and optoelectronic (eg, photodetectors, photovoltaics, and light emitting diodes) devices.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Layered rhenium disulfide (ReS2) field effect transistors (FETs), with thickness ranging from few to dozens of layers, are demonstrated on 20 nm thick HfO2/Si substrates. A small threshold voltage of ...−0.25 V, high on/off current ratio of up to ∼107, small subthreshold swing of 116 mV/dec, and electron carrier mobility of 6.02 cm2/V·s are obtained for the two-layer ReS2 FETs. Low-frequency noise characteristics in ReS2 FETs are analyzed for the first time, and it is found that the carrier number fluctuation mechanism well describes the flicker (1/f) noise of ReS2 FETs with different thicknesses. pH sensing using a two-layer ReS2 FET with HfO2 as a sensing oxide is then demonstrated with a voltage sensitivity of 54.8 mV/pH and a current sensitivity of 126. The noise characteristics of the ReS2 FET-based pH sensors are also examined, and a corresponding detection limit of 0.0132 pH is obtained. Our studies suggest the high potential of ReS2 for future low-power nanoelectronics and biosensor applications.
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IJS, KILJ, NUK, PNG, UL, UM
2D layered materials turn out to be the most attractive hotspot in materials for their unique physical and chemical properties. A special class of 2D layered material refers to materials exhibiting ...phase transition based on environment variables. Among these materials, transition metal dichalcogenides (TMDs) act as a promising alternative for their unique combination of atomic‐scale thickness, direct bandgap, significant spin–orbit coupling and prominent electronic and mechanical properties, enabling them to be applied for fundamental studies as catalyst materials. Metal phosphorous trichalcogenides (MPTs), as another potential catalytic 2D phase transition material, have been employed for their unusual intercalation behavior and electrochemical properties, which act as a secondary electrode in lithium batteries. The preparation of 2D TMD and MPT materials has been extensively conducted by engineering their intrinsic structures at the atomic scale. In this study, advanced synthesis methods of preparing 2D TMD and MPT materials are tested, and their properties are investigated, with stress placed on their phase transition. The surge of this type of report is associated with water‐splitting catalysis and other catalytic purposes. This study aims to be a guideline to explore the mentioned 2D TMD and MPT materials for their catalytic applications.
2D phase transition materials, including transition metal dichalcogenides (TMDs) and metal phosphorous trichalcogenides (MPTs), attract researchers' interests for their unique combination of large surface area, direct bandgap, intrigue chemical, and mechanical properties. Great efforts are devoted to preparing 2D TMD and MPT materials by engineering their intrinsic structures at the atomic scale, aiming to achieve active catalyst toward catalytic purposes.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Highlights
The growth of high-quality single-crystalline Te nanobelts is reported by introducing atomically flat hexagonal boron nitride (h-BN) nanoflakes into the chemical vapor deposition system as ...the growth substrate.
The field-effect transistor based on Te grown on h-BN exhibits an ultrahigh hole mobility up to 1370 cm
2
V
−1
s
−1
at room temperature.
The lack of stable
p
-type van der Waals (vdW) semiconductors with high hole mobility severely impedes the step of low-dimensional materials entering the industrial circle. Although
p
-type black phosphorus (bP) and tellurium (Te) have shown promising hole mobilities, the instability under ambient conditions of bP and relatively low hole mobility of Te remain as daunting issues. Here we report the growth of high-quality Te nanobelts on atomically flat hexagonal boron nitride (h-BN) for high-performance
p
-type field-effect transistors (FETs). Importantly, the Te-based FET exhibits an ultrahigh hole mobility up to 1370 cm
2
V
−1
s
−1
at room temperature, that may lay the foundation for the future high-performance
p
-type 2D FET and metal–oxide–semiconductor (p-MOS) inverter. The vdW h-BN dielectric substrate not only provides an ultra-flat surface without dangling bonds for growth of high-quality Te nanobelts, but also reduces the scattering centers at the interface between the channel material and the dielectric layer, thus resulting in the ultrahigh hole mobility
.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Over the past decade, two-dimensional (2D) transition metal dichalcogenides (TMDCs) have attracted tremendous research interest for future electronics owing to their atomically thin thickness, ...compelling properties and various potential applications. However, interface engineering including contact optimization and channel modulations for 2D TMDCs represents fundamental challenges in ultimate performance of ultrathin electronics. This article provides a comprehensive overview of the basic understanding of contacts and channel engineering of 2D TMDCs and emerging electronics benefiting from these varying approaches. In particular, we elucidate multifarious contact engineering approaches such as edge contact, phase engineering and metal transfer to suppress the Fermi level pinning effect at the metal/TMDC interface, various channel treatment avenues such as van der Waals heterostructures, surface charge transfer doping to modulate the device properties, and as well the novel electronics constructed by interface engineering such as diodes, circuits and memories. Finally, we conclude this review by addressing the current challenges facing 2D TMDCs towards next-generation electronics and offering our insights into future directions of this field.
This review presents recent advances and challenges in the interface engineering of 2D TMDCs and emerging electronics based on TMDCs.
2D layered materials such as graphene and transition‐metal dichalcogenides (TMDCs) have emerged as promising candidates for next‐generation nanoelectronic applications due to their atomically thin ...thicknesses and unique electronic properties. Among TMDCs, molybdenum disulfide (MoS2) has been extensively investigated as a channel material for field‐effect transistor (FET) and circuit realization. However, to date most reported works have been limited to exfoliated MoS2 nanosheets primarily due to the difficulty in synthesizing large‐area and high‐quality MoS2 thin film. A demonstration of wafer‐scale monolayer MoS2 synthesis is reported by chemical vapor deposition (CVD), enabling transistors, memristive memories, and integrated circuits to be realized simultaneously. Specifically, building on top‐gated FETs with a high‐κ gate dielectric (HfO2), Boolean logic circuits including inverters and NAND gates are successfully demonstrated using direct‐coupled FET logic technology, with typical inverters exhibiting a high voltage gain of 16, a large total noise margin of 0.72 VDD at VDD = 3 V, and perfect logic‐level matching. Additionally, resistive switching is demonstrated in a MoS2‐based memristor, indicating that they have great potential for the development of resistive random‐access memory. By virtue of scalable CVD growth capability, the way toward practical and large‐scale electronic applications of MoS2 is indicated.
Continuous wafer scale monolayer MoS2 is synthesized via chemical vapor deposition on a sapphire substrate. Electronic devices (transistors and memristors) and logic circuits (inverters and NAND gates) are demonstrated through a fabrication process fully compatible with existing Si technology. This work paves the way toward unleashing the potential of atomically thin MoS2 for practical and large‐scale electronics.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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