Long-Wavelength Lead Sulfide Quantum Dots Sensing up to 2600 nm for Short-Wavelength Infrared Photodetectors

Dong, Chen; Liu, Shuyi; Barange, Nilesh; Lee, Jaewoong; Pardue, Tyler N.; Yi, Xinjian; Yin, Shichen; So, Franky

doi:10.1021/acsami.9b16539

Cited by 62 publications

(63 citation statements)

References 32 publications

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“…The uncapped QD synthesis followed the original synthetic route as developed by Hines and Scholes; however, modifications were included to better control size and size dispersity. ,, …”

Section: Methodsmentioning

confidence: 99%

“…The uncapped QD synthesis followed the original synthetic route as developed by Hines and Scholes; 7 however, modifications were included to better control size and size dispersity. 6,53,54 2.4 nm PbS QDs. For these reactions, the Pb solution was prepared by adding 0.223 g (1 mmol) of lead oxide, 1.9 mL of OA (6 mmol), 0.395 mL of OLA (1.2 mmol) and 25 mL of ODE in a three-neck round-bottom flask.…”

Section: ■ Methodsmentioning

confidence: 99%

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Anisotropic, Nonthermal Lattice Disordering Observed in Photoexcited PbS Quantum Dots

et al. 2021

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Given their nanoscale dimensions, colloidal semiconductor nanocrystals provide unique systems for investigating the dynamics controlling surface chemistry and fundamental issues regarding lattice reorganization upon changes in electron distribution. These systems are particularly amenable to ultrafast electron probes, offering an atomic level picture of the lattice reorganization involved following photoexcitation. Here, we study lead sulfide (PbS) quantum dots with ultrafast electron diffraction to characterize the atomic motions following high-intensity photoexcitation. Short-range nonthermal lattice distortions and increased atomic disorder were observed in PbS colloidal quantum dots ranging from 2.4 to 8.7 nm in size. These effects scaled inversely with size and were less pronounced in nanocrystals with a chloride-containing surface rather than only organic ligands, which is consistent with an effect arising at the surface. The anisotropic, nonthermal lattice disordering occurs preferentially along the (100) crystallographic directions, which could indicate an anisotropic distribution of localized charge between the differing lattice terminations of the {111} and {100} crystal facets. This is consistent with the larger anharmonicity for the lattice potential at lattice sites with reduced ligand coordination relative to the bulk, which has been shown to cause accelerated relaxation into dynamic and static surface trap sites. Through an exploration of quantum dot size and variation in surface termination, this work provides the missing structural details to advance our understanding and control of charge-carrier formation, trapping, and recombination processes in nanoscale semiconductor systems.

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“…The uncapped QD synthesis followed the original synthetic route as developed by Hines and Scholes; however, modifications were included to better control size and size dispersity. ,, …”

Section: Methodsmentioning

confidence: 99%

Section: ■ Methodsmentioning

confidence: 99%

Anisotropic, Nonthermal Lattice Disordering Observed in Photoexcited PbS Quantum Dots

et al. 2021

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“…[3,[11][12][13][14][15][16][17][18] In particular, recent studies have focused on PbS quantum dot photodiode (QDPD) structures because of their high energy conversion efficiency [18][19][20] and high response speed. [11,21,22] To achieve high performance PbS QDPDs, many studies have been conducted to improve the photon-electron conversion efficiency in the devices based on n + n-p architec ture-for example, with ZnO thin films serving as the electron transport layer (ETL), halidepassivated PbS CQD (PbS halide) thin films as the active layer, and ethanedithiol (EDT)passivated PbS (PbS EDT) CQD thin films as the hole transport layer (HTL). Exten sive studies have been conducted to improve light absorbance by utilizing the microcavity effect of oxide/metal/oxide multi layers, [23] plasmonic effect of metal nanostructures, [24,25] and blade coating which increases the active layer thickness.…”

Section: Suppressing the Dark Current In Quantum Dot Infrared Photodetectors By Controlling Carrier Statisticsmentioning

confidence: 99%

Suppressing the Dark Current in Quantum Dot Infrared Photodetectors by Controlling Carrier Statistics

Jung

Woo

Shin

et al. 2021

Advanced Optical Materials

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Lead sulfide colloidal quantum dot photodiodes (PbS QDPDs) exhibit a high energy conversion efficiency for infrared detection. Despite the high photoinduced current, the performance of PbS QDPDs is limited by the high dark current which is rarely investigated. Understanding the dark current in PbS QDPDs is critical to improving the detectivity of PbS QDPDs. Herein, it is demonstrated that minority carriers of I‐passivated PbS films and trap sites of EDT‐passivated PbS films are related to the dark current of PbS QDPD. Utilizing annealing and low‐temperature ligand exchange processes, the dark current density can be decreased almost tenfold by suppressing the minority carrier diffusion in the PN junction and trap‐assisted charge injection from the electrode. PN junction simulation, space charge limited current measurements, as well as structural, optical, and chemical characterizations are conducted to elucidate the origins of the dark current suppression. The authors achieve the lowest dark current density of 2.9 × 10−5 mA cm−2 at −1 V among PbS‐based QDPDs and a high detectivity of 6.7 × 1012 Jones at 980 nm. It is believed that this work provides fundamental understanding of carrier statistics in nanomaterials and device performance as well as a technological basis for realizing low‐cost high‐performance optoelectronic devices.

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“…In recent years, the broadband spectrum photodetectors have piqued the interest of researchers working in a variety of fields, including environmental monitoring, biological sensing, and digital cameras [1][2][3][4][5]. Generally, photodetectors that can operate in a broad spectrum range, from visible to shortwavelength infrared (SWIR) region, are required for these applications.…”

Section: Introductionmentioning

confidence: 99%

Lead Selenium Colloidal Quantum Dots for 400‐2600 nm Broadband Photodetectors

Liu

Xie

et al. 2022

Journal of Nanomaterials

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By the photodetector manufactured using traditional semiconductor materials, such as HgCdTe and InGaAs, it is difficult to broaden the application range of such photodetectors due to their high cost and complex manufacturing process. PbSe colloidal quantum dots (CQDs) have the potential to shift the working range of photodetector from visible to infrared wavelength region, and it also has high photoresponsivity. Herein, we report the characterization of PbSe CQDs synthesized using a facile solution process, as well as the relationship between the size of nanocrystal and the reaction temperature. The films of PbSe CQDs are deposited using the layer-by-layer (LbL) spin-coating method, which is then used to fabricate the photoconductive device. The fabricated device is found to have an efficient response in a broad spectrum range of 400-2600 nm. The device maintains good responsivity of ~320 mA/W at room temperature. Its external quantum efficiency was quite high in the shorter wavelength infrared region, and it has approximately 14% external quantum efficiency (EQE) at 2520 nm. The device demonstrated excellent performance, confirming that PbSe colloidal quantum dots is a promising material for future broadband spectrum photodetectors.

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Long-Wavelength Lead Sulfide Quantum Dots Sensing up to 2600 nm for Short-Wavelength Infrared Photodetectors

Cited by 62 publications

References 32 publications

Anisotropic, Nonthermal Lattice Disordering Observed in Photoexcited PbS Quantum Dots

Anisotropic, Nonthermal Lattice Disordering Observed in Photoexcited PbS Quantum Dots

Suppressing the Dark Current in Quantum Dot Infrared Photodetectors by Controlling Carrier Statistics

Lead Selenium Colloidal Quantum Dots for 400‐2600 nm Broadband Photodetectors

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