Effect of Thermal Cross-Linking of 4-Ethynylstyryl Capping Groups on Electronic Coupling between Silicon Quantum Dots in Silicon Quantum Dot Solids

2017 ◽  
Vol 121 (29) ◽  
pp. 15957-15969 ◽  
Author(s):  
Thu-Huong Le ◽  
Ki-Jeong Kim ◽  
Hyun-Dam Jeong
2016 ◽  
Vol 18 (37) ◽  
pp. 25837-25851 ◽  
Author(s):  
Bibhuti Bhusan Sahu ◽  
Yongyi Yin ◽  
Sven Gauter ◽  
Jeon Geon Han ◽  
Holger Kersten

The authors growth and microstructure of a silicon quantum dot film by tailoring the plasma chemistry and deposition energy are studied.


2009 ◽  
Vol 93 (9) ◽  
pp. 1524-1530 ◽  
Author(s):  
X.J. Hao ◽  
E.-C. Cho ◽  
G. Scardera ◽  
Y.S. Shen ◽  
E. Bellet-Amalric ◽  
...  

2019 ◽  
Vol 43 (22) ◽  
pp. 8660-8668 ◽  
Author(s):  
Jinzhu Wu ◽  
Beibei Li ◽  
Yaxiu Feng ◽  
Yanbin Shao ◽  
Xiaohong Wu ◽  
...  

A MoS2/rGO nanocomposite with a unique sandwich structure is synthesized by using silicon quantum dots (SiQDs), exhibiting excellent electrochemical performance for supercapacitors.


2018 ◽  
Vol 10 (34) ◽  
pp. 4129-4135 ◽  
Author(s):  
Lei Zhang ◽  
ZhaoRong Tang ◽  
YongPing Dong

Water dispersible silicon quantum dots (SiQDs) were synthesized by in situ growth under microwave irradiation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sinan Bugu ◽  
Shimpei Nishiyama ◽  
Kimihiko Kato ◽  
Yongxun Liu ◽  
Shigenori Murakami ◽  
...  

AbstractWe demonstrate the measurement of p-channel silicon-on-insulator quantum dots at liquid helium temperatures by using a radio frequency (rf) reflectometry circuit comprising of two independently tunable GaAs varactors. This arrangement allows observing Coulomb diamonds at 4.2 K under nearly best matching condition and optimal signal-to-noise ratio. We also discuss the rf leakage induced by the presence of the large top gate in MOS nanostructures and its consequence on the efficiency of rf-reflectometry. These results open the way to fast and sensitive readout in multi-gate architectures, including multi qubit platforms.


2020 ◽  
Author(s):  
Alyxandra Thiessen ◽  
Lijuan Zhang ◽  
Anton Oliynyk ◽  
Haoyang Yu ◽  
Kevin O'Connor ◽  
...  

<p>Two quantum dots, both alike in composition, but differing in structure, where we lay our scene. From broader classes, to bring deeper understanding, to the crystalline core that drives the quantum dot's sheen. In this contribution we examine two families of silicon quantum dots (SiQDs) that bring to mind the Capulets and the Montagues in Shakespeare’s Romeo and Juliet because of their stark similarities and differences. SiQDs are highly luminescent, heavy-metal-free and based upon earth-abundant elements. As such, they have attracted attention for far reaching applications ranging from biological imaging to luminescent solar concentrators to light-emitting diodes that rely on their size-dependent optical response. Unfortunately, correlating SiQD “size” to their photoluminescence maximum is often challenging. Herein, we provide essential structural insight into the correlation of SiQD dimension and PL maximum through a direct comparison of samples that exhibit statistically identical physical dimensions (d<sub>TEM</sub>) and chemical compositions, but different crystallite size (d<sub>XRD</sub>) and PL maxima. We then expand the scope of this investigation and systematically compare groupings of SiQDs: one in which the d<sub>XRD</sub> and d<sub>TEM</sub> agree and one where d<sub>XRD </sub>< d<sub>TEM</sub>. This latter comparison clearly shows d<sub>XRD</sub> better predicts SiQD optical response when using the well-established effective mass approximation. </p>


Author(s):  
Mai Xuan Dung ◽  
Mai Van Tuan ◽  
Pham Truong Long ◽  
Nguyen Thi Mai

Water-soluble, biocompatible, and highly luminescence carbon quantum dots (CQDs) have synthesized successfully from a citric acid (CA) and ethylenediamine (EDA) by using different approaches. Although the emission quantum yield of CQDs could be as high as 80% their emission spectrum is usually dominated by surface fluorophore groups and maximized at about 450 nm. Herein, we examined the effects of acid and amine precursors on the photoluminescence (PL) of resulting CQDs by systematic comparison the optical properties of CQDs obtained from CA, PA (phthalic acid) and EDA, ANL (aniline). UV-vis and PL spectroscopic studies revealed that the absorption onset varied from 325 nm to 400 nm while PL maximum changed from 390 nm to 450 nm by engineering acid and amine precursors. The emission quantum yield was also changed from 9 to 70%, depending on the used acid-amine precursors.  Keywords Carbon quantum dots, hydrothermal synthesis, color tuning, photoluminescence, acid, amine References K. Wang, Z. Gao, G. Gao, Y. Wo, Y. Wang, G. Shen, D. Cui, Systematic safety evaluation on photoluminescent carbon dots, Nanoscale Res. Lett. 8 (2013) 1–9. doi:10.1186/1556-276X-8-122.[2] K. Jiang, S. Sun, L. Zhang, Y. Lu, A. Wu, C. Cai, H. Lin, Red, Green, and Blue Luminescence by Carbon Dots: Full-Color Emission Tuning and Multicolor Cellular Imaging, Angew. Chemie Int. Ed. 54 (2015) 5360–5363. doi:10.1002/anie.201501193.[3] M.X. Dung, P. Mohapatra, J.K. Choi, J.H. Kim, S. Jeong, H.D. Jeong, InP quantum dot-organosilicon nanocomposites, Bull. Korean Chem. Soc. 33 (2012) 1491–1504. doi:10.5012/bkcs.2012.33.5.1491.[4] X. Mai, Q. Hoang, The Large-Scale Synthesis of Vinyl-Functionalized Silicon Quantum Dot and Its Application in Miniemulsion Polymerization, J. Nanomater. 2016 (2016).[5] M.X. Dung, D.D. Tung, S. Jeong, H.D. Jeong, Tuning optical properties of Si quantum dots by ??-conjugated capping molecules, Chem. - An Asian J. 8 (2013) 653–664. doi:10.1002/asia.201201099.[6] M.X. Dung, H.D. Jeong, Synthesis of styryl-terminated silicon quantum dots: Reconsidering the use of methanol, Bull. Korean Chem. Soc. 33 (2012) 4185–4187.doi:10.5012/bkcs.2012.33.12.4185.[7] V.-T. Mai, N.H. Duong, X.-D. Mai, Surface Polarity Controls the Optical Properties of One-Pot Synthesized Silicon Quantum Dots, Chem. Phys. (2018).doi:10.1016/j.chemphys.2018.11.012.[8] V.-T. Mai, Q. Hoang, X. Mai, Enhanced Red Emission in Ultrasound-Assisted Sol-Gel Derived ZnO/PMMA Nanocomposite, Adv. Mater. Sci. Eng. 2018 (2018) 1–8. doi:10.1155/2018/7252809.[9] J. Schneider, C.J. Reckmeier, Y. Xiong, M. Von Seckendorff, A.S. Susha, P. Kasak, A.L. Rogach, Molecular fluorescence in citric acid-based carbon dots, J. Phys. Chem. C. 121 (2017) 2014–2022. doi:10.1021/acs.jpcc.6b12519.[10] F. Ehrat, S. Bhattacharyya, J. Schneider, A. Löf, R. Wyrwich, A.L. Rogach, J.K. Stolarczyk, A.S. Urban, J. Feldmann, Tracking the Source of Carbon Dot Photoluminescence: Aromatic Domains versus Molecular Fluorophores, Nano Lett. 17 (2017) 7710–7716. doi:10.1021/acs.nanolett.7b03863.[11] M. Shamsipur, A. Barati, A.A. Taherpour, M. Jamshidi, Resolving the Multiple Emission Centers in Carbon Dots: From Fluorophore Molecular States to Aromatic Domain States and Carbon-Core States, J. Phys. Chem. Lett. 9 (2018) 4189–4198. doi:10.1021/acs.jpclett.8b02043.[12] T.H.T. Xuan-Dung Mai, Quang-Bac Hoang, Hong Quan To, Phuong Le Thi, The synthesis of highly luminescent carbon quantum dots, (2017) (47)20-26.[13] M.X.D. Lê Thị Phượng, Lê Quang Trung, Đỗ Thị Thu Hòa, Doãn Diệu Thúy, Ảnh hưởng của tỷ lệ Acid/Amine đến cấu trúc bề mặt và hiệu suất phát xạ của chấm lượng tử carbon, (2018) (55) 67-74.[14] M.V.T. Hoàng Quang Bắc, Trần Thu Hương, Đinh Thị Châm, Nguyễn Thị Loan, Nguyễn Thị Quỳnh, Bùi Thị Huệ, Lê Thị Thùy Hương, Mai Xuân Dũng, Nghiên cứu tổng hợp hạt nano huỳnh quang từ một số rau củ quả, (2017) 4(40), 70-73.[15] Y. Song, S. Zhu, S. Zhang, Y. Fu, L. Wang, X. Zhao, B. Yang, Investigation from chemical structure to photoluminescent mechanism: a type of carbon dots from the pyrolysis of citric acid and an amine, J. Mater. Chem. C. 3 (2015) 5976–5984. doi:10.1039/C5TC00813A.[16] T.H. Ngà, B.T. Hạnh, M.X. Dũng, Tính toán lượng tử làm rõ tính chất quang học của chấm lượng tử carbon, Tạp Chí KHoa Học - Đại Học Sư Phạm Hà Nội 2. 56 (2018).[17] S. Zhu, Q. Meng, L. Wang, J. Zhang, Y. Song, H. Jin, K. Zhang, H. Sun, H. Wang, B. Yang, Highly photoluminescent carbon dots for multicolor patterning, sensors, and bioimaging, Angew. Chemie - Int. Ed. 52 (2013) 3953–3957. doi:10.1002/anie.201300519.[18] Q.-B. Hoang, V.-T. Mai, D.-K. Nguyen, D.Q. Truong, X.-D. Mai, Crosslinking induced photoluminescence quenching in polyvinyl alcohol-carbon quantum dot composite, Mater. Today Chem. 12 (2019) 166–172. doi:10.1016/j.mtchem.2019.01.003.


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