Growth of high-quality self-catalyzed core-shell GaAsP nanowires on Si substrates

2016 ◽  
Author(s):  
Yunyan Zhang ◽  
Martin Aagesen ◽  
Ana M. Sanchez ◽  
Jiang Wu ◽  
Richard Beanland ◽  
...  
Keyword(s):  
Core Shell ◽  
High Quality ◽  
Si Substrates

High-Temperature Synthesis of CdSe-Based Core/Shell, Core/Shell/Shell, and Core/Graded-Shell Nanoplatelets for Stable and Efficient Narrowband Emitters

2019 ◽  
Author(s):  
Aurelio A. Rossinelli ◽  
Henar Rojo ◽  
Aniket S. Mule ◽  
Marianne Aellen ◽  
Ario Cocina ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Temperature ◽  
Equilibrium Shape ◽  
Size Variation ◽  
Crystal Defects ◽  
Atomic Scale ◽  
Quantum Yields ◽  
Core Shell ◽  
Compositional Gradient ◽  
High Quality

<div>Colloidal semiconductor nanoplatelets exhibit exceptionally narrow photoluminescence spectra. This occurs because samples can be synthesized in which all nanoplatelets share the same atomic-scale thickness. As this dimension sets the emission wavelength, inhomogeneous linewidth broadening due to size variation, which is always present in samples of quasi-spherical nanocrystals (quantum dots), is essentially eliminated. Nanoplatelets thus offer improved, spectrally pure emitters for various applications. Unfortunately, due to their non-equilibrium shape, nanoplatelets also suffer from low photo-, chemical, and thermal stability, which limits their use. Moreover, their poor stability hampers the development of efficient synthesis protocols for adding high-quality protective inorganic shells, which are well known to improve the performance of quantum dots. <br></div><div>Herein, we report a general synthesis approach to highly emissive and stable core/shell nanoplatelets with various shell compositions, including CdSe/ZnS, CdSe/CdS/ZnS, CdSe/Cd<sub>x</sub>Zn<sub>1–x</sub>S, and CdSe/ZnSe. Motivated by previous work on quantum dots, we find that slow, high-temperature growth of shells containing a compositional gradient reduces strain-induced crystal defects and minimizes the emission linewidth while maintaining good surface passivation and nanocrystal uniformity. Indeed, our best core/shell nanoplatelets (CdSe/Cd<sub>x</sub>Zn<sub>1–x</sub>S) show photoluminescence quantum yields of 90% with linewidths as low as 56 meV (19.5 nm at 655 nm). To confirm the high quality of our different core/shell nanoplatelets for a specific application, we demonstrate their use as gain media in low-threshold ring lasers. More generally, the ability of our synthesis protocol to engineer high-quality shells can help further improve nanoplatelets for optoelectronic devices.</div>

scholarly journals Epitaxial Growth of Ordered In-Plane Si and Ge Nanowires on Si (001)

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 788
Author(s):  
Jian-Huan Wang ◽  
Ting Wang ◽  
Jian-Jun Zhang
Keyword(s):  
Electron Microscopy ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
Core Shell ◽  
High Quality ◽  
Quantum Devices ◽  
Wafer Scale ◽  
Transmission Electron ◽  
Controllable Growth

Controllable growth of wafer-scale in-plane nanowires (NWs) is a prerequisite for achieving addressable and scalable NW-based quantum devices. Here, by introducing molecular beam epitaxy on patterned Si structures, we demonstrate the wafer-scale epitaxial growth of site-controlled in-plane Si, SiGe, and Ge/Si core/shell NW arrays on Si (001) substrate. The epitaxially grown Si, SiGe, and Ge/Si core/shell NW are highly homogeneous with well-defined facets. Suspended Si NWs with four {111} facets and a side width of about 25 nm are observed. Characterizations including high resolution transmission electron microscopy (HRTEM) confirm the high quality of these epitaxial NWs.

Phase transition and piezoelectricity of sol–gel-processed Sm-doped BiFeO3 thin films on Pt(111)/Ti/SiO2/Si substrates

2015 ◽  
Vol 3 (9) ◽  
pp. 2115-2122 ◽  
Author(s):  
Wei Sun ◽  
Jing-Feng Li ◽  
Qi Yu ◽  
Li-Qian Cheng
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Sol Gel ◽  
Orthorhombic Phase ◽  
High Quality ◽  
Si Substrates ◽  
Bifeo3 Thin Films ◽  
Gel Processing

We prepared high-quality Bi1−xSmxFeO3 films on Pt(111)/Ti/SiO2/Si substrates by sol–gel processing and found rhombohedral–orthorhombic phase transition with enhanced piezoelectricity.

Effect of Ge on SiC Film Morphology in SiC/Si Films Grown by MOCVD

1999 ◽  
Vol 572 ◽  
Author(s):  
W. L. Samey ◽  
L. Salamanca-Riba ◽  
P. Zhou ◽  
M. G. Spencer ◽  
C. Taylor ◽  
...  
Keyword(s):  
Stacking Faults ◽  
Two Dimensional ◽  
High Quality ◽  
Flow Rates ◽  
Si Substrates ◽  
Cvd Growth ◽  
Polytype Transformation ◽  
Si Films ◽  
Sic Film ◽  
Sic Films

ABSTRACTSiC/Si films generally contain stacking faults and amorphous regions near the interface. High quality SiC/Si films are especially difficult to obtain since the temperatures usually required to grow high quality SiC are above the Si melting point. We added Ge in the form of GeH2 to the reactant gases to promote two-dimensional CVD growth of SiC films on (111) Si substrates at 1000°C. The films grown with no Ge are essentially amorphous with very small crystalline regions, whereas those films grown with GeH2 flow rates of 10 and 15 sccm are polycrystalline with the 3C structure. Increasing the flow rate to 20 sccm improves the crystallinity and induces growth of 6H SiC over an initial 3C layer. This study presents the first observation of spontaneous polytype transformation in SiC grown on Si by MOCVD.

Green and facile synthesis of high-quality water-soluble Ag-In-S/ZnS core/shell quantum dots with obvious bandgap and sub-bandgap excitations

2018 ◽  
Vol 753 ◽  
pp. 364-370 ◽  
Author(s):  
Yanyan Chen ◽  
Qiang Wang ◽  
Tianyong Zha ◽  
Jigang Min ◽  
Jingying Gao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Water Soluble ◽  
Core Shell ◽  
Facile Synthesis ◽  
High Quality ◽  
Quality Water

One-pot synthesis of ultrasmall β-NaGdF4 nanoparticles with enhanced upconversion luminescence

2019 ◽  
Vol 7 (29) ◽  
pp. 8898-8904 ◽  
Author(s):  
Chunyan Cheng ◽  
Yueshan Xu ◽  
Songtao Liu ◽  
Yuanyuan Liu ◽  
Xian Wang ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Upconversion Luminescence ◽  
Core Shell ◽  
High Quantum Yield ◽  
High Quality ◽  
Shell Nanoparticles ◽  
One Pot ◽  
High Quantum ◽  
One Pot Synthesis ◽  
Core Shell Nanoparticles

High quality β-NaGdYF4:Yb/Er and high quantum yield β-NaGdF4:Yb/Er@β-NaYF4 core shell nanoparticles were synthesized.

Low-temperature fabrication of high-quality (Ba, Sr)TiO3 films using charged liquid cluster beam method

2002 ◽  
Vol 17 (8) ◽  
pp. 1888-1891 ◽  
Author(s):  
Hyungsoo Choi ◽  
Sungho Park ◽  
Yi Yang ◽  
HoChul Kang ◽  
Kyekyoon (Kevin) Kim ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Low Temperature ◽  
Cluster Beam ◽  
High Quality ◽  
Carboxylate Ligands ◽  
Si Substrates ◽  
Beam Method ◽  
Temperature Deposition ◽  
Bst Films ◽  
Substrate Temperatures

Low-temperature deposition of high-quality (Ba, Sr)TiO3 (BST) thin films was achieved in air on Pt/Ti/SiO2/Si substrates using the charged liquid cluster beam (CLCB) method. The Ba, Sr, and Ti precursors were synthesized using alkoxy carboxylate ligands to tailor their physical properties to the CLCB process. The as-deposited BST films fabricated at substrate temperatures as low as 280 °C exhibited high purity. The leakage current density and dielectric constant of the film, deposited at 300 °C and subsequently annealed at 700 °C, were 2.5 × 10−9 A/cm2 at 1.5 V and 305, respectively.

One-Pot Fabrication of High-Quality InP/ZnS (Core/Shell) Quantum Dots and Their Application to Cellular Imaging

ChemPhysChem ◽  
2009 ◽  
Vol 10 (9-10) ◽  
pp. 1466-1470 ◽  
Author(s):  
Sahid Hussain ◽  
Nayoun Won ◽  
Jutaek Nam ◽  
Jiwon Bang ◽  
Hyokyun Chung ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cellular Imaging ◽  
Core Shell ◽  
High Quality ◽  
One Pot

Epitaxial Growth of Aluminum Nitride on Sapphire and Silicon

1994 ◽  
Vol 358 ◽  
Author(s):  
K. Dovidenko ◽  
S. Oktyabrsky ◽  
J. Narayan ◽  
M. Razeghi
Keyword(s):  
Epitaxial Growth ◽  
Substrate Surface ◽  
Wide Band ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
High Quality ◽  
Microstructural Characteristics ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTThe microstructural characteristics of wide band gap semiconductor, hexagonal A1N thin films on Si(100), (111), and sapphire (0001) and (10ī2) were studied by transmission electron microscopy (TEM) and x-ray diffraction. The films were grown by MOCVD from TMA1 + NH3 + N2 gas mixtures. Different degrees of film crystallinity were observed for films grown on α-A12O3 and Si substrates in different orientations. The epitaxial growth of high quality single crystalline A1N film on (0001) α-Al2O3 was demonstrated with a dislocation density of about 2*10 10cm−2 . The films on Si(111) and Si(100) substrates were textured with the c-axis of A1N being perpendicular to the substrate surface.

Sign in / Sign up

Export Citation Format

Share Document