skip to main content

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 more » 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. « less
Authors:
Award ID(s):
1809293 1909292 1508494
Publication Date:
NSF-PAR ID:
10180878
Journal Name:
Infrared Technology and Applications XLVI, Vol 11407 (2020) SPIE Defense + Commercial Sensing (2020)
Volume:
11407
Page Range or eLocation-ID:
7
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.
  2. 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.
  3. 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.
  4. Broadband photodetectors (PDs) have great applications in both industrial and scientific sectors. In this study, solution-processed broadband PDs with an “inverted” vertical photodiode device structure without incorporating transparent conductive oxides electrodes, fabricated by bulk heterojunction (BHJ) composites composed of a low optical gap conjugated polymer blended with highly electrically conductive PbS quantum dots (QDs), operated at room temperature, are reported. The low optical gap conjugated polymer incorporated with PbS QDs contributes to the spectral response from the ultraviolet (UV)-visible to the infrared (IR) range. To realize the IR spectral response and to circumvent the weak IR transparency of the transparent oxide electrodes, the implementation of a photodiode with an “inverted” vertical device structure with the Au anode and the Ba/Al bilayer semitransparent cathode passivated with the MgF 2 layer is demonstrated. Photoinduced charge carrier transfer occurring within the BHJ composite gave rise to decent photocurrent, resulting in detectivities greater than 10 12 Jones (cm Hz 1/2 /W) over the wavelength from the UV-visible to the IR range under low applied bias. Thus, our findings of the utilization of the BHJ composites and an “inverted” vertical photodiode without the incorporation of the transparent conductive oxide electrodes provide a facile way tomore »realize broadband PDs.« less
  5. High-performance hybrid graphene photodetectors were prepared with endohedral fullerenes deposited on graphene using electrophoretic methods for the first time. Endohedral Sc 3 N@C 80 , which acts as an electron acceptor, was used and the ensuing electronic and optoelectronic properties were measured. Another endohedral fullerene, La@C 82 , was also adsorbed on graphene, which acts as an electron donor. Upon optical illumination, for the Sc 3 N@C 80 –graphene hybrid, the photoinduced free holes are injected into graphene, increasing the hole carrier concentration in graphene, while the photoexcited electrons remain in Sc 3 N@C 80 ; this leads to a high photoresponsivity  of ∼10 9 A W −1 , detectivity D of ∼10 15 Jones, and external quantum efficiency EQE ∼ 10 9 % for the Sc 3 N@C 80 –graphene hybrid. This  is ∼10 times higher compared to other reports of quantum dot-graphene and few layer MoS 2 –graphene heterostructures. Similarly, for the La@C 82 –graphene hybrid,  ∼ 10 8 A W −1 , D ∼ 10 14 Jones, and EQE ∼ 10 6 % were achieved, with electrons being injected into graphene. The exceptional performance gains achieved with both types of hybrid structures confirms themore »potential of endohedrals to dope graphene for high performance optoelectronic devices using a facile and scalable fabrication process.« less