skip to main content

Attention:

The NSF Public Access Repository (NSF-PAR) system and access will be unavailable from 11:00 PM ET on Friday, April 12 until 2:00 AM ET on Saturday, April 13 due to maintenance. We apologize for the inconvenience.


Title: Explore uncooled quantum dots/graphene nanohybrid infrared detectors based on quantum dots/graphene heterostructures
Heterojunction nanohybrids based on low-dimension semiconductors, including colloidal quantum dots (QDs) and 2D atomic materials (graphene, transition metal chalcogenides, etc) provide a fascinating platform to design of new photonic and optoelectronic devices that take advantages of the enhanced light-solid interaction attributed to their strong quantum confinement and superior charge mobility for uncooled photodetectors with a high gain up to 1010. In these heterojunction nanohybrids, the van der Waals (vdW) interface plays a critical role in controlling the optoelectronic process including exciton dissociation by the interface built-in field that drives the follow-up charge injection and transport to graphene. In this paper, we present our recent progress in development of such heterostructures nanohybrids for uncooled infrared detectors including PbS and FeS2 QDs/graphene and 2D vdW heterostructures MoTe2/Graphene/SnS2 and GaTe/InSe. We have found that nonstoichiometric Fe1–xS2 QDs (x = 0.01–0.107) with strong localized surface plasmonic resonance (LSPR) can have much enhanced absorption in broadband from ultraviolet to short-wave infrared (SWIR, 1–3 μm). Consequently, the LSPR Fe1–xS2 QDs/graphene heterostructure photodetectors exhibit extraordinary photoresponsivity in exceeding 4.32 ×106 A/W and figure-of-merit detectivity D* < 7.50 ×1012 Jones in the broadband of UV–Vis–SWIR at room temperature. The 2D vdW heterostructures allows novel designs of interface band alignments with uncooled NIR-SWIR D* up to 1012 Jones. These results illustrate that the heterostructure nanohybrids provide a promising pathway for low-cost, printable and flexible infrared detectors and imaging systems.  more » « less
Award ID(s):
1809293 1909292 1508494
NSF-PAR ID:
10180878
Author(s) / Creator(s):
Date Published:
Journal Name:
Infrared Technology and Applications XLVI, Vol 11407 (2020) SPIE Defense + Commercial Sensing (2020)
Volume:
11407
Page Range / eLocation ID:
7
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Fulop, Gabor F. ; Kimata, Masafumi ; Zheng, Lucy ; Andresen, Bjørn F. ; Miller, John Lester (Ed.)
    Colloidal semiconductor quantum dots/graphene van der Waals (vdW) heterojunctions take advantages of the enhanced light-matter interaction and spectral tenability of quantum dots (QDs) and superior charge mobility in graphene, providing a promising alternative for uncooled infrared photodetectors with a gain or external quantum efficiency up to 1010. In these QD/graphene vdW heterostructures, the QD/graphene interface plays a critical role in controlling the optoelectronic process including exciton dissociation, charge injection and transport. Specifically, charge traps at the vdW interface can increase the noise, reduce the responsivity and response speed. This paper highlight our recent progress in engineering the vdW heterojunction interface towards more efficient charge transfer for higher photoresponsivity, D* and response speed. These results illustrate that the importance in vdW heterojunction interface engineering in QD/graphene photodetectors which may provide a promising pathway for low-cost, printable and flexible infrared detectors and imaging systems. 
    more » « less
  2. Tong, Xin ; Wu, Jiang ; Wang, Zhiming (Ed.)
    Colloidal semiconductor quantum dot/graphene van der Waals heterostructure nanohybrids are emerging technologies for photodetection. These nanohybrids combine the advantages of the enhanced light-matter interaction and spectral tunability of quantum dots (QDs) and superior charge mobility in graphene, providing an affordable alternative for uncooled photodetectors with high gain or external quantum efficiency in a wide spectral range. In particular, the interfacing of QDs with high-mobility graphene as a charge transport pathway has provided an effective resolution to the critical issue of charge transport in QD-only photodetectors stemming from the low charge mobility associated with both QD surface defect states and QD-QD junctions. Furthermore, the achieved capability in industrial-scale fabrication of graphene, colloidal QDs, and QD/graphene nanohybrids has motivated efforts in researches of focal plane arrays that are expected to be not only high performance and low cost but also lightweight, flexible, and wearable. This chapter aims to provide an up-to-date review of the recent progress made in the research of QD/graphene nanohybrid photodetectors, together with a discussion on the challenges remaining and perspective in future research and development to make QD/graphene nanohybrids competitive for commercialization. 
    more » « less
  3. Abstract

    2D atomic sheets of transition metal dichalcogenides (TMDs) have a tremendous potential for next‐generation optoelectronics since they can be stacked layer‐by‐layer to form van der Waals (vdW) heterostructures. This allows not only bypassing difficulties in heteroepitaxy of lattice‐mismatched semiconductors of desired functionalities but also providing a scheme to design new optoelectronics that can surpass the fundamental limitations on their conventional semiconductor counterparts. Herein, a novel 2D h‐BN/p‐MoTe2/graphene/n‐SnS2/h‐BN p–g–n junction, fabricated by a layer‐by‐layer dry transfer, demonstrates high‐sensitivity, broadband photodetection at room temperature. The combination of the MoTe2and SnS2of complementary bandgaps, and the graphene interlayer provides a unique vdW heterostructure with a vertical built‐in electric field for high‐efficiency broadband light absorption, exciton dissociation, and carrier transfer. The graphene interlayer plays a critical role in enhancing sensitivity and broadening the spectral range. An optimized device containing 5−7‐layer graphene has been achieved and shows an extraordinary responsivity exceeding 2600 A W−1with fast photoresponse and specific detectivity up to ≈1013Jones in the ultraviolet–visible–near‐infrared spectrum. This result suggests that the vdW p–g–n junctions containing multiple photoactive TMDs can provide a viable approach toward future ultrahigh‐sensitivity and broadband photonic detectors.

     
    more » « less
  4. Abstract

    Van der Waals (vdW) heterostructures of 2D atomically thin layered materials (2DLMs) provide a unique platform for constructing optoelectronic devices by staking 2D atomic sheets with unprecedented functionality and performance. A particular advantage of these vdW heterostructures is the energy band engineering of 2DLMs to achieve interlayer excitons through type‐II band alignment, enabling spectral range exceeding the cutoff wavelengths of the individual atomic sheets in the 2DLM. Herein, the high performance of GaTe/InSe vdW heterostructures device is reported. Unexpectedly, this GaTe/InSe vdWs p–n junction exhibits extraordinary detectivity in a new shortwave infrared (SWIR) spectrum, which is forbidden by the respective bandgap limits for the constituent GaTe (bandgap of ≈1.70 eV in both the bulk and monolayer) and InSe (bandgap of ≈1.20–1.80 eV depending on thickness reduction from bulk to monolayer). Specifically, the uncooled SWIR detectivity is up to ≈1014Jones at 1064 nm and ≈1012Jones at 1550 nm, respectively. This result indicates that the 2DLM vdW heterostructures with type‐II band alignment produce an interlayer exciton transition, and this advantage can offer a viable strategy for devising high‐performance optoelectronics in SWIR or even longer wavelengths beyond the individual limitations of the bandgaps and heteroepitaxy of the constituent atomic layers.

     
    more » « less
  5. Abstract Semiconductor quantum dots/graphene heterostructure nanohybrids combine the advantages of the enhanced light–matter interaction and spectral tunability of quantum dots (QDs) and high charge mobility in graphene as a charge transport pathway, providing a unique platform for exploration of photodetectors with high performance. In particular, the QDs/graphene nanohybrids allow resolution to the critical issue of charge transport in QDs-only photodetectors stemming from the low charge mobility associated with both QD surface defect states and inter-QD junctions. Furthermore, the achieved capability in industrial-scale fabrication of graphene and colloidal QDs has motivated efforts in research of QDs/graphene nanohybrids focal plane arrays that are expected to be not only high performance and low cost, but also light-weight, flexible and wearable. This paper aims to highlight recent progress made in the research and development of QDs/graphene nanohybrid photodetectors and discuss the challenges remained towards their commercial applications. 
    more » « less