In this work, high-responsivity graphene photodetectors operating in the middle-wavelength infrared (MWIR) spectral band were fabricated by taking advantage of photo-gating effect. Graphene-based field effect transistors on indium antimonide (InSb) substrates. The InSb generated photo-carriers response to incident IR light modulated channel gate voltage and induced a large photocurrent. These graphene-based exhibited clear photoresponse during irradiation with 4.6 μm MWIR laser an ultrahigh...

We have combined a graphene field-effect transistor (GFET) and surface acoustic wave (SAW) sensor on LiTaO3 substrate to create (GSAW) sensor. When SAW propagates in graphene, an acoustoelectric current (IA) flows between two attached electrodes. This has unique electrical characteristics, having both positive negative peak values with respect the electrolyte-gate voltage (VEg) solution. found that IA is controlled by VEg amplitude of SAW. It was also confirmed GSAW detects changes charge...

Metal-insulator-metal-based plasmonic metamaterial absorbers (MIM-PMAs) generate strong localized surface plasmon resonance (LSPR) on their surfaces. Therefore, MIM-PMAs are expected to enhance the absorption of graphene coated Graphene-coated (GMIM-PMAs) were developed and optical properties investigated both experimentally numerically at infrared wavelengths. Significant modification GMIM-PMAs was achieved only in main LSPR wavelength region, where insulator is lossless. The enhancement...

Graphene is a promising new material for photodetectors due to its excellent optical properties and high-speed response. However, graphene-based phototransistors have low responsivity the weak light absorption of graphene. We observed giant Dirac point shift upon white illumination in with n-doped Si substrates, but not those p-doped substrates. The source-drain current substrate were investigated without both p-type n-type decay time drain-source indicates that substrate, SiO2 layer, metal...

Graphene/semiconductor heterojunction photodetectors have the potential to outperform conventional infrared (IR) sensors. A high-performance graphene/indium antimonide (InSb) photodetector for high-resolution mid-IR image sensors was developed using an undoped InSb substrate with low carrier density. The width of depletion layer at graphene/InSb interface increased because density InSb, which resulted in a dark current proposed device. In addition, capacitance change due photocarrier...

Low dark current, high-responsivity middle-wavelength infrared (IR) graphene photodetectors using photo-gating amplification of injected photo-carriers are demonstrated. A graphene/p-indium antimonide (InSb) heterojunction and graphene/insulator region were formed. The from InSb to amplified by induced in the graphene/tetraethyl orthosilicate (TEOS) region, resulting high responsivity low current performance. 14.9 A/W an ON/OFF ratio 2.66×104 achieved. photoresponse is shown be determined...

This report describes high-responsivity, long-wavelength infrared graphene photodetectors operating at room temperature, that are based on the photogating effect. Photogating is enhanced by a pyroelectric effect in lithium niobium oxide (LiNbO3) substrate due to heat generation as result of radiation absorption SiN layer substrate. significantly modulates back-gate voltage, and increases photoresponse factor approximately 600. Switching charge carrier type observed response higher light...

Abstract The acoustic charge transportation induced by surface wave (SAW) propagation in graphene solution was investigated. sign of current ( I A ) found to switch when crossing the Dirac point because major carrier transitioned from holes electrons change electrolyte-gate voltage. also exhibited a peak value under conditions both hole and electron conduction. These results can be explained on basis type graphene, as well mobility graphene.

Abstract A p–n junction was developed in a graphene transistor by simple photolithography process used typical semiconductor processes. The p- and n-type regions were formed coating photoresist on part of the channel immersion uncovered region alkali developer, respectively. 3-fold enhancement photocurrent observed at maximum field effect mobility. It is therefore important to maximize mobility doping photocurrent. results obtained here are an step toward production high-sensitivity...

This study presents high-responsivity graphene-based deep-ultraviolet (DUV) photodetectors using chemical vapor deposition (CVD)-hexagonal boron nitride (h-BN) photogating. To improve the DUV photoresponse, h-BN was used as a photosensitizer in graphene field-effect transistors (GFETs). The photosensitizers were synthesized CVD and then transferred onto SiO 2 /Si substrate. behavior of irradiated with light investigated cathodoluminescence UV–VIS reflectance. Under 260 nm light, it exhibited...

Abstract High-responsivity graphene photodetectors were fabricated using turbostratic stacked graphene, which provided enhanced photogating. Photogating is a promising means of increasing the responsivity photodetectors, and this effect proportional to carrier mobility. Turbostratic exhibits higher mobility than conventional monolayer because it has same band structure as while preventing scattering by underlying SiO 2 layer. The photoresponse these devices at wavelength 642 nm was...

Graphene-based transistors were investigated as simple photodetectors for a broad range of wavelengths. Graphene prepared using p-doped silicon (Si) substrates with SiO2 layer, and source drain electrodes. Monolayer graphene was fabricated by chemical vapor deposition transferred onto the substrates, channel region then formed. The photoresponse measured in broadband wavelength from visible, near-infrared (NIR), mid- to long-wavelength IR (MWIR LWIR) regions. enhanced photogating induced Si...

We demonstrated a middle-wavelength infrared (MWIR) graphene photodetector using the photogating effect. This effect was induced by photosensitizers situated around channel that coupled incident light and generated large electrical charge. The graphene-based MWIR consisted of top channel, source–drain electrodes, an insulator layer, photosensitizer, its photoresponse characteristics were determined current measurements. Irradiation vacuum cooled device laser clear photoresponse, as evidenced...

One-dimensional plasmonic nanogratings (1D-PNGs) with high aspect ratios and narrow grooves promise enhanced coupling for hybrid graphene systems the localized surface plasmon of metallic grating plasmons. However, both fabrication 1D-PNG application to it are difficult. We developed 1D-PNGs a ratio 15 100 nm in width using tapered mold method dry graphene-transfer procedure. Raman spectroscopy measurements showed that monolayer was successfully transferred onto 1D-PNGs, strongly doped Au...

Graphene, which is carbon arranged in atomically thin sheets, has drawn significant attention many fields due to its unique electronic and optical properties. Photodetectors are particularly strong candidates for graphene applications the need a broadband photoresponse from ultraviolet terahertz regions, high-speed operation, low fabrication costs, have not been achieved with present technology. Here, graphene-based transistors were investigated as simple photodetectors broad range of...

Graphene/semiconductor heterojunction-based photodetectors are expected to achieve high performance in various wavelength regions. Graphene photogated diodes (GPDs) based on such heterojunctions promising for the fabrication of high-performance photodetectors, which cannot be achieved using conventional technologies. However, their action mechanism has not yet been theoretically demonstrated. In this study, we investigated GPDs with and without an interfacial layer. We demonstrated that thin...

We employ turbostratic stacked chemical vapor deposition (CVD) graphene for a mid-wavelength infrared (MWIR) photodetector using the photogating effect. Turbostratic CVD was fabricated by multiple transfer processes. Graphene field effect transistor-based MWIR photodetectors were developed an InSb substrate. The of three layers enhanced both field-effect mobility and response approximately times, compared to that conventional single-layer in vacuum at 77 K. Our results may contribute...

The photoresponse mechanism of graphene/InSb heterojunction middle-wavelength infrared (MWIR) photodetectors was investigated. devices comprised a as carrier-injection region and an insulator graphene on tetraethyl orthosilicate (TEOS) for photogating. MWIR significantly amplified with increase in the graphene/TEOS cross-sectional area by covering entire detector graphene. graphene-channel dependence indicated that carrier density modulated photocarrier accumulation at TEOS/InSb boundary,...

Graphene infrared (IR) photodetectors are promising devices that exploit the unique optoelectronic properties of graphene, such as broadband light absorption, rapid response, and high-chemical stability. However, graphene has low absorbance (2.3%), which limits its photo-responsivity. This study investigated middle-wavelength (MWIR) long-wavelength IR (LWIR) responsivity enhancements in with type-II superlattices (T2SL) employed photosensitizers. field-effect transistors (GFETs) were...

Graphene has promising applications for novel optoelectronic devices. However, graphene-based photodetectors have two major drawbacks that need attention. The first is how to preserve graphene’s original high carrier mobility, and the second enhance absorption improve its performance. Hexagonal boron nitride (hBN)/graphene van der Waals (vdW) heterostructure-based plasmonic metasurfaces (PMs) are proposed wavelength-selective infrared (IR) photodetectors. hBN preserves PMs absorption....

Advanced functional infrared (IR) photodetectors with wavelength selectivity are promising for a wide range of applications, such as multicolor imaging, gas analysis and biomedical analysis. Graphene is considered to be material novel IR detectors. However, the absorption graphene constant at approximately 2.3% rather small. We have developed multispectral high-performance using metal-insulator-metal (MIM) or single-layer (SL) plasmonic metasurfaces (PMs). MIM- SL-PMs induce localized...