scispace - formally typeset
Search or ask a question
Proceedings ArticleDOI

High-performance ultraviolet detector employing out-of-plane rGO/MoS 2 PN heterostructure

TL;DR: In this paper, an ultraviolet detector employing an in-plane transport channel of n-type MoS 2 with out-of-plane p-type rGO, which acts as a sensitizer for underlying N-type photodetector, was demonstrated.
Abstract: We demonstrated an ultraviolet detector employing an in-plane transport channel of n-type MoS 2 with out-of-plane p-type rGO, which acts as a sensitizer for underlying n-type MoS 2 photodetector. A developed vertical built-in field from vertical p-n nano-heterojunction separates the photo-excited carriers at the rGO/MoS 2 interface. Therefore, the rGO/MoS 2 device showed a notably improved photo-responsivity of $\sim$ 6.92 A)/W and an excellent detectivity of 1.26 $\times$ 1012 Jones under the irradiation of ultraviolet light. Moreover, the device exhibited an excellent reproducibility and stability in ambient environment even after four months.
References
More filters
Journal ArticleDOI
TL;DR: Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena can now be mimicked and tested in table-top experiments.
Abstract: Graphene is a rapidly rising star on the horizon of materials science and condensed-matter physics. This strictly two-dimensional material exhibits exceptionally high crystal and electronic quality, and, despite its short history, has already revealed a cornucopia of new physics and potential applications, which are briefly discussed here. Whereas one can be certain of the realness of applications only when commercial products appear, graphene no longer requires any further proof of its importance in terms of fundamental physics. Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena, some of which are unobservable in high-energy physics, can now be mimicked and tested in table-top experiments. More generally, graphene represents a conceptually new class of materials that are only one atom thick, and, on this basis, offers new inroads into low-dimensional physics that has never ceased to surprise and continues to provide a fertile ground for applications.

35,293 citations


"High-performance ultraviolet detect..." refers background in this paper

  • ...However, its zero bandgap do not make it suitable in photonics and opto-electronics devices applications due to its short carrier lifetime and high dark current [2]....

    [...]

Journal ArticleDOI
24 Jan 2012-ACS Nano
TL;DR: The unique characteristics of incident-light control, prompt photoswitching, and good photoresponsivity from the MoS(2) phototransistor pave an avenue to develop the single-layer semiconducting materials for multifunctional optoelectronic device applications in the future.
Abstract: A new phototransistor based on the mechanically exfoliated single-layer MoS2 nanosheet is fabricated, and its light-induced electric properties are investigated in detail. Photocurrent generated from the phototransistor is solely determined by the illuminated optical power at a constant drain or gate voltage. The switching behavior of photocurrent generation and annihilation can be completely finished within ca. 50 ms, and it shows good stability. Especially, the single-layer MoS2 phototransistor exhibits a better photoresponsivity as compared with the graphene-based device. The unique characteristics of incident-light control, prompt photoswitching, and good photoresponsivity from the MoS2 phototransistor pave an avenue to develop the single-layer semiconducting materials for multifunctional optoelectronic device applications in the future.

3,033 citations


"High-performance ultraviolet detect..." refers background in this paper

  • ...26 × 1012 Jones), respectively which are better than that of many others 2D material based photodetectors [9],[1113]....

    [...]

  • ...In pristine MoS2, mostly photoexcited carriers recombine before reaching on electrode due to low carrier life time [9]....

    [...]

Journal ArticleDOI
TL;DR: This work shows that the fluctuations are significantly reduced in suspended graphene samples and reports low-temperature mobility approaching 200,000 cm2 V-1 s-1 for carrier densities below 5 x 109 cm-2, which cannot be attained in semiconductors or non-suspended graphene.
Abstract: The discovery of graphene1,2 raises the prospect of a new class of nanoelectronic devices based on the extraordinary physical properties3,4,5,6 of this one-atom-thick layer of carbon. Unlike two-dimensional electron layers in semiconductors, where the charge carriers become immobile at low densities, the carrier mobility in graphene can remain high, even when their density vanishes at the Dirac point. However, when the graphene sample is supported on an insulating substrate, potential fluctuations induce charge puddles that obscure the Dirac point physics. Here we show that the fluctuations are significantly reduced in suspended graphene samples and we report low-temperature mobility approaching 200,000 cm2 V−1 s−1 for carrier densities below 5 × 109 cm−2. Such values cannot be attained in semiconductors or non-suspended graphene. Moreover, unlike graphene samples supported by a substrate, the conductivity of suspended graphene at the Dirac point is strongly dependent on temperature and approaches ballistic values at liquid helium temperatures. At higher temperatures, above 100 K, we observe the onset of thermally induced long-range scattering. The novel electronic properties of graphene can be compromised when it is supported on an insulating substrate. However, suspended graphene samples can display low-temperature mobility values that cannot be attained in semiconductors or non-suspended graphene, and the conductivity approaches ballistic values at liquid-helium temperatures.

2,977 citations

Journal ArticleDOI
TL;DR: A gain of ∼10(8) electrons per photon and a responsivity of ∼ 10(7) A W(-1) in a hybrid photodetector that consists of monolayer or bilayer graphene covered with a thin film of colloidal quantum dots is demonstrated.
Abstract: A phototransistor in which electric charges are absorbed by colloidal quantum dots and circulated in graphene exhibits high values for gain, responsivity and specific detectivity.

1,921 citations


"High-performance ultraviolet detect..." refers methods in this paper

  • ...Meanwhile, hole moved in rGO and the conduction of MoS2 channel was controlled by these accumulated holes using photo-gating effect through capacitive coupling [16]....

    [...]

Posted Content
TL;DR: In this article, the authors exploit the strong light absorption in quantum dots and the two-dimensionality and high mobility of graphene to merge these materials into a hybrid system for photodetection with extremely high sensitivity.
Abstract: Graphene has emerged as a novel platform for opto-electronic applications and photodetector, but the inefficient conversion from light to current has so far been an important roadblock. The main challenge has been to increase the light absorption efficiency and to provide a gain mechanism where multiple charge carriers are created from one incident photon. Here, we take advantage of the strong light absorption in quantum dots and the two-dimensionality and high mobility of graphene to merge these materials into a hybrid system for photodetection with extremely high sensitivity. Exploiting charge transfer between the two materials, we realize for the first time, graphene-based phototransistors that show ultrahigh gain of 10^8 and ten orders of magnitude larger responsivity compared to pristine graphene photodetectors. These hybrid graphene-quantum dot phototransistors exhibit gate-tunable sensitivity, spectral selectivity from the shortwave infrared to the visible, and can be integrated with current circuit technologies.

1,462 citations

Related Papers (5)