Near-Infrared Photodetectors Based on Hybrid Graphene-Colloidal PbSe Quantum Dots

MRS Advances ◽  
2020 ◽  
Vol 5 (44) ◽  
pp. 2273-2280
Author(s):  
Wafaa Gebril ◽  
Haider Salman ◽  
M. Omar Manasreh
Keyword(s):  
Quantum Dots ◽  
Near Infrared ◽  
Response Spectrum ◽  
Spectral Response ◽  
Hybrid Structure ◽  
Absorbance Spectrum ◽  
Optical Absorbance ◽  
Exfoliated Graphene ◽  
Current Voltage ◽  
Hot Injection

AbstractPhotodetectors based on a hybrid structure of graphene sensitized with lead selenide (PbSe) colloidal quantum dots (QDs) effective in the near-infrared (NIR) region with high responsivity were investigated. Colloidal PbSe nanocrystals were synthesized via a hot injection method. The bandgap of the synthesized nanocrystals was determined to be 0.68 eV by measuring their optical absorbance spectrum. Photodetectors based on PbSe QDs were investigated to examine their functionality. These devices were characterized by measuring the current-voltage curves in the dark and light and the spectral response spectrum. A photodetector was fabricated using a multilayer mechanically exfoliated graphene on a Si/SiO2 substrate with a PbSe QDs layer on top. A responsivity and detectivity of 1265A/W and 3.4 *1010cm.Hz0.5/W respectively were calculated based on current-voltage measurements.

Enhanced photocurrent due to interband transitions from InAs quantum dots embedded in InGaAs quantum well solar cells

2013 ◽  
Vol 1551 ◽  
pp. 143-148
Author(s):  
R. Vasan ◽  
Y. F. M. Makableh ◽  
J. C. Sarker ◽  
M. O. Manasreh
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Open Circuit Voltage ◽  
Spectral Response ◽  
Power Conversion ◽  
Open Circuit ◽  
Interband Transitions ◽  
Inas Quantum Dots ◽  
Current Voltage ◽  
Current Voltage Characteristics

ABSTRACTSolar cells based on InAs quantum dots embedded in InxGa1-xAs quantum wells grown on n-type GaAs substrate were fabricated and tested. Solar cells with In mole fraction (x) in the range of 0-40% were investigated. The performance of the solar cells was evaluated using current-voltage characteristics, spectral response, and quantum efficiency measurements. The spectral response and quantum efficiency spectra possess several peaks along the lower energy side of the spectra, which are attributed to the interband transitions in the structure. These peaks are red shifted as x is increased above 0 %. The device power conversion efficiency was extracted from the current-voltage characteristics using an AM 1.5 solar simulator. The short circuit current density increased as the x is increased above 0 %. But the overall power conversion efficiency decreased due to decrease in the open circuit voltage. The decrease in open circuit voltage is due strain induced dislocations caused by lattice mismatch.

scholarly journals PEGylated-folic acid–modified black phosphorus quantum dots as near-infrared agents for dual-modality imaging-guided selective cancer cell destruction

Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2425-2435 ◽  
Author(s):  
Jing Wang ◽  
Dong Liang ◽  
Zehua Qu ◽  
Ivan M. Kislyakov ◽  
Valery M. Kiselev ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Folic Acid ◽  
Cancer Cells ◽  
Near Infrared ◽  
Processing System ◽  
Black Phosphorus ◽  
Optical Absorbance ◽  
Present Design ◽  
Black Phosphorus Quantum Dots

AbstractBiological systems have high transparence to 700–1100-nm near-infrared (NIR) light. Black phosphorus quantum dots (BPQDs) have high optical absorbance in this spectrum. This optical property of BPQDs integrates both diagnostic and therapeutic functions together in an all-in-one processing system in cancer theranostic approaches. In the present study, BPQDs were synthesized and functionalized by targeting moieties (PEG-NH2-FA) and were further loaded with anticancer drugs (doxorubicin) for photodynamic–photothermal–chemotherapy. The precise killing of cancer cells was achieved by linking BPQDs with folate moiety (folic acid), internalizing BPQDs inside cancer cells with folate receptors and NIR triggering, without affecting the receptor-free cells. These in vitro experiments confirm that the agent exhibited an efficient photokilling effect and a light-triggered and heat-induced drug delivery at the precise tumor sites. Furthermore, the nanoplatform has good biocompatibility and effectively obliterates tumors in nude mice, showing no noticeable damages to noncancer tissues. Importantly, this nanoplatform can inhibit tumor growth through visualized synergistic treatment and photoacoustic and photothermal imaging. The present design of versatile nanoplatforms can allow for the adjustment of nanoplatforms for good treatment efficacy and multiplexed imaging, providing an innovation for targeted tumor treatment.

Enhanced response in InAs quantum dots in an InGaAs quantum well solar cells by anti-reflection coatings

2013 ◽  
Vol 1551 ◽  
pp. 155-161
Author(s):  
Y. F. Makableh ◽  
R. Vasan ◽  
J. C. Sarker ◽  
S. Lee ◽  
M. A. Khan ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Solar Cell ◽  
Quantum Well ◽  
Spectral Response ◽  
Sol Gel ◽  
Absorption Enhancement ◽  
Inas Quantum Dots ◽  
Current Voltage ◽  
Before And After

ABSTRACTA study on light absorption enhancement of an InAs quantum dots embedded into InxGa1-xAs quantum well with GaAs as a barrier solar cells was carried out. Solar cell devices were fabricated from different structures, which were grown by using molecular beam epitaxy, with the In mole fraction (x) varied between 0 – 25 %. Poly-L-Lysine ligands and ZnO sol-gel was used to modify the surface of the solar cells and act as anti-reflection coatings. The anti-reflection characteristic of the ligands and the sol-gel were investigated by measuring the solar cell characteristics before and after the solar cells surface modifications. The current-voltage characteristics were measured of the fabricated solar cells before and after Poly-L-Lysine and ZnO coatings. A significant enhancement on the order of 40 % of the solar cells performance was observed. This type of enhancement was observed in the power conversion efficiency, spectral response measurements, and external quantum efficiency.

Preparation of near‐infrared Ag 2 S quantum dots for detection of bisphenol A in water

2018 ◽  
Vol 13 (1) ◽  
pp. 112-116 ◽  
Author(s):  
Yanling Hu ◽  
Chun Deng ◽  
Yu He ◽  
Yili Ge ◽  
Gongwu Song
Keyword(s):  
Quantum Dots ◽  
Bisphenol A ◽  
Near Infrared

Analysis of the Bias Dependent Spectral Response of a-SiC:H p-i-n Photodiode

2002 ◽  
Vol 715 ◽  
Author(s):  
P. Louro ◽  
A. Fantoni ◽  
Yu. Vygranenko ◽  
M. Fernandes ◽  
M. Vieira
Keyword(s):  
Bias Voltage ◽  
Voltage Dependence ◽  
Spectral Response ◽  
Surface Recombination ◽  
Electrical Field ◽  
Field Reversal ◽  
Current Voltage ◽  
Voltage Dependent ◽  
And Inversion ◽  
Device Operation

AbstractThe bias voltage dependent spectral response (with and without steady state bias light) and the current voltage dependence has been simulated and compared to experimentally obtained values. Results show that in the heterostructures the bias voltage influences differently the field and the diffusion part of the photocurrent. The interchange between primary and secondary photocurrent (i. e. between generator and load device operation) is explained by the interaction of the field and the diffusion components of the photocurrent. A field reversal that depends on the light bias conditions (wavelength and intensity) explains the photocurrent reversal. The field reversal leads to the collapse of the diode regime (primary photocurrent) launches surface recombination at the p-i and i-n interfaces which is responsible for a double-injection regime (secondary photocurrent). Considerations about conduction band offsets, electrical field profiles and inversion layers will be taken into account to explain the optical and voltage bias dependence of the spectral response.

Electrically Driven Near-Infrared Broadband Light Source with Gaussian-Like Spectral Shape Based on Multiple InAs Quantum Dots

2016 ◽  
Vol E99.C (3) ◽  
pp. 381-384 ◽  
Author(s):  
Takuma YASUDA ◽  
Nobuhiko OZAKI ◽  
Hiroshi SHIBATA ◽  
Shunsuke OHKOUCHI ◽  
Naoki IKEDA ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Light Source ◽  
Near Infrared ◽  
Spectral Shape ◽  
Inas Quantum Dots ◽  
Broadband Light Source

scholarly journals Metalorganic chemical vapor deposition of InN quantum dots and nanostructures

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Caroline E. Reilly ◽  
Stacia Keller ◽  
Shuji Nakamura ◽  
Steven P. DenBaars
Keyword(s):  
Quantum Dots ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Near Infrared ◽  
Optoelectronic Devices ◽  
Chemical Vapor ◽  
Electromagnetic Spectrum ◽  
Material System ◽  
Metalorganic Chemical

AbstractUsing one material system from the near infrared into the ultraviolet is an attractive goal, and may be achieved with (In,Al,Ga)N. This III-N material system, famous for enabling blue and white solid-state lighting, has been pushing towards longer wavelengths in more recent years. With a bandgap of about 0.7 eV, InN can emit light in the near infrared, potentially overlapping with the part of the electromagnetic spectrum currently dominated by III-As and III-P technology. As has been the case in these other III–V material systems, nanostructures such as quantum dots and quantum dashes provide additional benefits towards optoelectronic devices. In the case of InN, these nanostructures have been in the development stage for some time, with more recent developments allowing for InN quantum dots and dashes to be incorporated into larger device structures. This review will detail the current state of metalorganic chemical vapor deposition of InN nanostructures, focusing on how precursor choices, crystallographic orientation, and other growth parameters affect the deposition. The optical properties of InN nanostructures will also be assessed, with an eye towards the fabrication of optoelectronic devices such as light-emitting diodes, laser diodes, and photodetectors.

Employing CuInS2 quantum dots modified with vancomycin for detecting Staphylococcus aureus and iron(Ⅲ)

2021 ◽  
Author(s):  
Ziang Guo ◽  
Xiaowei Huang ◽  
Zhihua Li ◽  
Jiyong Shi ◽  
Xuetao Hu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Quantum Dots ◽  
Biological Tissue ◽  
Near Infrared ◽  
Cuins2 Quantum Dots ◽  
Tissue Permeability

This paper describes a Near-infrared quantum dots (CuInS2 QDs)/antibiotics (vancomycin) nanoparticle-based assay for Staphylococcus aureus and iron(Ⅲ) detection. CuInS2 QDs with good biological tissue permeability and biocompatibility are combined with...

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