Journal of Physical Chemistry C
·
2022
·
IF 4.177
Kseniia A. Sergeeva,Kezhou Fan,Aleksandr A. Sergeev,Sile Hu,Haochen Liu,Christopher C. Chan,Stephen V. Kershaw,Kam Sing Wong,Andrey L. Rogach
We investigate the charge carrier dynamics in HgTe quantum dots emitting in the second near-infrared window (1000–2500 nm). To provide a link between fundamental physics and practical application, we made consistent studies of the charge carrier dynamics evolution for quantum dots in different states: colloidal solutions of quantum dots capped with a long-chain ligand; thin films made from them; and finally, exchanged to short-chain ligand films suitable for field effect transistor based devices. Ultrafast transient absorption spectroscopy reveals an ultralow Auger-related nonradiative relaxation threshold at 0.1 exciton per quantum dot, both in colloidal solutions and solid films, with a rate of 30 ns–1. The exchange from long- to short-chain ligands causing closer packing of the HgTe quantum dots leads to a strong increase of the Auger recombination rate of up to 100 ns–1. The competition between the Auger process and excitonic recombination significantly affects the performance of HgTe-based thin film photodetectors operating at room temperature, resulting in a 2 orders of magnitude drop in responsivity when the excitation flux was increased from 0.01 to 5 W·cm–2.
研究领域:
材料科学
·
光子学
·
纳米技术
·
光电子学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED MATERIALS
·
2023
·
IF 29.4
Kseniia A. Sergeeva,Sile Hu,Anastasiia V. Sokolova,Arsenii S. Portniagin,Desui Chen,Stephen V. Kershaw,Andrey L. Rogach
A large volume, scalable synthesis procedure of HgTe quantum dots (QDs) capped initially with short-chain conductive ligands ensures ligand exchange-free and simple device fabrication. An effective n- or p-type self-doping of HgTe QDs is achieved by varying cation–anion ratio, as well as shifting the Fermi level position by introducing single- or double-cyclic thiol ligands, that is, 2-furanmethanethiol (FMT) or 2,5-dimercapto-3,4-thiadiasole (DMTD) in the synthesis. This allows for preserving the intact surface of the HgTe QDs, thus ensuring a one order of magnitude reduced surface trap density compared with HgTe subjected to solid-state ligand exchange. The charge carrier diffusion length can be extended from 50 to 90 nm when the device active area consists of a bi-layer of cation-rich HgTe QDs capped with DMTD and FMT, respectively. As a result, the responsivity under 1340 nm illumination is boosted to 1 AW −1 at zero bias and up to 40 AW −1 under −1 V bias at room temperature. Due to high noise current density, the specific detectivity of these photodetectors reaches up to 10 10 Jones at room temperature and under an inert atmosphere. Meanwhile, high photoconductive gain ensures a rise in the external quantum efficiency of up to 1000% under reverse bias.
研究领域:
材料科学
·
纳米技术
·
光电子学
·
半导体物理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Electronic Materials
·
2026
·
IF 4.7
Runze Huang,Mengxuan Yu,Xingchen Zhang,Xudong Hu,Xi Ran,Mohan Yuan,Jun Ouyan,Jungang He,Xinzheng Lan
HgTe colloidal quantum dots (CQDs) possess an ultra-broad spectral response, good air stability, and tunable surface chemistry, making them a promising candidate material for next-generation infrared photodetectors. However, the development of HgTe CQD infrared photodetectors has been hindered by the limited availability of favorable hole transport layers (HTLs). Herein, we report high-quality HTLs based on CdTe/HgTe core/shell CQDs. The CdTe/HgTe CQDs were synthesized via a facile cation exchange strategy using CdTe CQDs. Based on the CdTe/HgTe CQD HTL, a p-on-n structure HgTe CQD photodiode was fabricated. An external quantum efficiency of 50.5% and a specific detectivity D* of 1.73 × 1012 Jones at a wavelength of 1600 nm were achieved. Subsequently, the device was successfully employed for infrared imaging. This study identifies a facile approach for the fabrication of high-quality HTLs for HgTe CQD photodiodes.
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DOI
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Hao Yang,Qiong Zhang,Ruiguang Chang,Zhenghui Wu,Huaibin Shen
As potential low-cost alternatives of traditional bulk HgCdTe crystals, HgTe colloidal quantum dots (CQDs) synthesized through reactions between HgCl2 and trioctylphosphine-telluride in hot oleylamine have shown promising performances in mid-wave infrared photodetectors. Tetrapodic or tetrahedral HgTe CQDs have been obtained by tuning the reaction conditions such as temperature, reaction time, concentrations, and ratios of the two precursors. However, the principles governing the growth dynamics and the mechanism behind the transitions between tetrapodic and tetrahedral HgTe CQDs have not been sufficiently understood. In this work, synthesis of HgTe CQDs through bilateral injection is introduced to study the growth mechanism. It suggests that tetrahedral HgTe CQDs usually result from the breaks of tetrapodic HgTe CQDs after their legs grow thick enough. The fundamental factor determining whether the growth makes their legs longer or thicker is the effective concentration of the Te precursor during the growth, rather than temperature, Hg-rich environment, or reactivity of precursors. A chemical model is proposed to illustrate the principles governing the growth dynamics, which provides valuable guidelines for tuning the material properties of HgTe CQDs according to the needs of applications.
研究领域:
纳米材料
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半导体量子点
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红外光电子学
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化学合成
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Zhezhe Wang,Liqing Yang,Shaorui Yuan,Bo Yao,Shupeng Cen,Libing Tang,Yude Wang
HgTe colloidal quantum dots (CQDs) are promising for infrared detection due to their broad spectral response, high photosensitivity, and potential for low-cost fabrication. However, conventional synthesis methods struggle to achieve precise size control, narrow size distribution, high monodispersity, and tetrahedral morphology. In this work, we introduce diphenylphosphine (DPP) to enhance the reactivity of the telluride precursor, promoting uniform nucleation and allowing precise control over CQDs morphology, size, and monodispersity. A dual regulation strategy based on synthesis temperature and thiol ligand alkyl chain length is further employed to enable controllable growth of CQDs in both size and shape. The organic-inorganic heterojunction short-wave infrared photodetector constructed using HgTe CQDs layers obtained via this method and an organic hole transport layer of PEDOT:PSS exhibits a responsivity of 652 mA/W at 1650 nm and a detection rate of 7.88 × 10 11 Jones at room temperature. This work presents a novel, cost-effective, and scalable strategy for synthesizing HgTe CQDs, laying a solid foundation for the development and commercialization of high-performance infrared photodetectors.
研究领域:
材料科学
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纳米技术
·
光电子学
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红外探测
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半导体量子点
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED MATERIALS
·
2026
·
IF 29.1
Zhourui Hu,Jingjing Liu,Yilu Qin,Yi Long,Lingfeng Ye,Na Lin,Yunxiang Di,Meikang Han,Gang Zhou,Kun Ba,Yan Chen,Xudong Wang,Tianle Guo,Junhao Chu,Jianlu Wang
Surface trap-induced carrier doping currently hinders colloidal quantum dots (CQDs) from approaching the electronic purity of epitaxial semiconductors, particularly in the mid-wave infrared (MWIR) regime, where low dark noise is critical. Here, we demonstrate that the coordination geometry of the metal halide precursor strongly influences passivation efficacy, suppressing background carrier densities to an intrinsic level (∼10 14 cm −3 ). Mechanistic investigation reveals that the octahedral geometry of HgBr 2 facilitates the formation of a stable HgBr 2 (Olam) 4 complex, as traced by the correlated evolution of chemical shifts in 1 H NMR and diffraction patterns in powder X-ray diffraction (pXRD). This behavior contrasts with the linear lattice of HgCl 2 , where the absence of comparable spectral evolution indicates much weaker ligand coordination. Consequently, the stable complex is structurally inherited by the HgTe CQDs, yielding a high surface halide coverage of ∼9 at.%, whereas HgCl 2 results in halide-deficient surfaces (<1 at.%). This robust passivation effectively suppresses non-radiative recombination, consistent with improved carrier decay dynamics in time-resolved photoluminescence (TRPL). Cross-verification via field-effect transistor (FET), capacitance-voltage (C-V), and Hall measurements confirms substantially reduced background doping, highlighting coordination engineering as an effective strategy for achieving electronic purity in solution-processed optoelectronics.
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2026
·
IF 7.8
Jing Liu,Mohan Yuan,Hang Xia,Ya Wang,Xudong Hu,Jun Ouyang,Xi Ran,Huicheng Hu,Xinzheng Lan
HgTe colloidal quantum dots (CQDs) hold great promise for the next generation of low-cost and large-format infrared imagers. The implementation of the ZnO/HgTe/ZnTe double heterojunction enables HgTe imagers in photovoltaic mode. However, it remains challenging to further improve the performance and stability of the detector. Here, we propose a hybrid passivation strategy employing methylammonium iodide (MAI) and HgI2 to address this challenge. This approach generates strongly bound X-type HgI3– ligands that effectively passivate the HgTe CQDs surface. The hybrid passivated HgTe CQDs demonstrate enhanced colloidal stability and surface passivation, which translate into improved detector performance and stability. The resulting photodetector achieves a remarkable external quantum efficiency (EQE) of 66.8% at 1620 nm under zero bias, a specific detectivity of 1.45 × 1012 Jones, and a dark current density as low as 185 nA/cm2. The HgTe CQD detectors were successfully integrated with thin-film transistor (TFT) readout circuits. The enhanced stability of the detectors based on hybrid passivated HgTe CQDs was verified at both the single-pixel and array levels.
✓ 已验证
DOI
PubMed
高影响因子
Nano Materials Science
·
2026
·
IF 20.5
Zhezhe Wang,Liqing Yang,Shaorui Yuan,Bo Yao,Zilian Zhang,Libin Tang,Yude Wang
HgTe colloidal quantum dots (CQDs) photodetectors, owing to their advantages of low cost and facile integration, are anticipated to be the optimal choice for the next-generation of short-wave infrared (SWIR) detection technology. However, narrow-bandgap HgTe CQDs exhibit a very high electron affinity, resulting in the conduction band energy level being excessively low. The energy levels of most electron transport layers (ETLs) are difficult to align, leading to a decrease in charge extraction efficiency. To address this issue, we developed a novel CdHgTe CQDs ETL film for the first time by utilizing the cation exchange strategy of CdTe CQDs. The exchange reaction of partly substituting Cd 2+ with Hg 2+ within the thin film can reduces the surface potential, increase its work function, and thereby facilitates favorable energy level matching with the HgTe CQDs layer, enabling the fabrication of a n-i-p HgTe CQDs SWIR photodetector with ultra-low dark current density characteristics, reaching as low as 9.45 × 10 −5 mA/cm 2 at −1.0 V bias, and a specific detectivity of 7.41 × 10 11 Jones at 1560 nm. Finally, we integrated it into a 64 × 64 SWIR imager and demonstrated its object recognition applications in various scenarios, thereby establishing a robust foundation for enriching the design of HgTe-based infrared detector devices and broadening their application scope.
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2026
·
IF 19.9
Kseniia A. Sergeeva,Anastasiia V. Sokolova,Chenxi Guo,Yuanfei Huo,Yulia V. Kuznetsova,Ran An,Aleksandr A. Sergeev,Kam Sing Wong,Tianshuo Zhao,Andrey L. Rogach
Enhancing the absorption of the photodetector's active layer within the target spectral range is a key strategy for improving the device performance. Strong near-field light localization in carefully engineered metal or oxide metasurfaces coupled to semiconductor quantum dots (QDs) enables efficient and wavelength-selective photodetection, but such structures are typically complex and require expensive fabrication. Here, we introduce an up-scalable, all-solution process to realize photodetectors operating in the extended short-wavelength infrared (ESWIR) range, using colloidal plasmonic In 2 O 3 :Sn,F (commonly abbreviated as ITO) nanocrystals (NCs) coupled to colloidal HgTe QDs, which boosts the optical absorption of HgTe QDs across the range from 1500 to 3000 nm. The responsivity of photodetectors to blackbody illumination reaches over 40 A/W within the 180–240 K temperature range, and the photocurrent spectrum is tailored thanks to the localized surface plasmon resonance of the ITO NCs. An In 2 O 3 shell further grown around ITO NCs allows us to suppress the dark current, albeit at the cost of the exciton-plasmon coupling strength. The specific detectivity remains in the range from 10 11 to 10 10 Jones as the operating temperature is varied from 160 to 260 K, establishing a pathway for all-colloidal materials-based ESWIR photodetectors compatible with cryogen-free cooling systems.
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 44
·2307660
·
IF 19
Kseniia A. Sergeeva,Dmitrii V. Pavlov,Albert A. Seredin,Eugeny V. Mitsai,Aleksandr A. Sergeev,Evgeny B. Modin,Anastasiia V. Sokolova,Tsz Chun Lau,Kseniia V. Baryshnikova,Mihail I. Petrov,Stephen V. Kershaw,Aleksandr A. Kuchmizhak,Kam Sing Wong,Andrey L. Rogach
In order to advance the development of quantum emitter-based devices, it is essential to enhance light-matter interactions through coupling between semiconductor quantum dots with high quality factor resonators. Here, efficient tuning of the emission properties of HgTe quantum dots in the infrared spectral region is demonstrated by coupling them to a plasmonic metasurface that supports bound states in the continuum. The plasmonic metasurface, composed of an array of gold nanobumps, is fabricated using single-step direct laser printing, opening up new opportunities for creating exclusive 3D plasmonic nanostructures and advanced photonic devices in the infrared region. A 12-fold enhancement of the photoluminescence in the 900–1700 nm range is observed under optimal coupling conditions. By tuning the geometry of the plasmonic arrays, controllable shaping of the emission spectra is achieved, selectively enhancing specific wavelength ranges across the emission spectrum. The observed enhancement and shaping of the emission are attributed to the Purcell effect, as corroborated by systematic measurements of radiative lifetimes and optical simulations based on the numerical solution of Maxwell's equations. Moreover, coupling of the HgTe photoluminescence to high quality factor modes of the metasurface improves emission directivity, concentrating output within an ≈20° angle.
研究领域:
光学
·
材料科学
·
纳米技术
·
量子物理
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）