scholarly journals Surface Passivation and Positive Band-Edge Shift of p-Si(111) Surfaces Functionalized with Mixed Methyl/Trifluoromethylphenylacetylene Overlayers

2020 ◽  
Vol 124 (30) ◽  
pp. 16338-16349
Author(s):  
Miguel Cabán-Acevedo ◽  
Kimberly M. Papadantonakis ◽  
Bruce S. Brunschwig ◽  
Nathan S. Lewis
Keyword(s):  
Surface Passivation ◽  
Band Edge ◽  
Positive Band

scholarly journals Core Nanoparticle Engineering for Narrower and More Intense Band-Edge Emission from AgInS2/GaSx Core/Shell Quantum Dots

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1763 ◽  
Author(s):  
Watcharaporn Hoisang ◽  
Taro Uematsu ◽  
Takahisa Yamamoto ◽  
Tsukasa Torimoto ◽  
Susumu Kuwabata
Keyword(s):  
Surface Passivation ◽  
Precursor Solution ◽  
Silver Sulfide ◽  
Band Edge ◽  
Crystal Phase ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Orthorhombic Crystal ◽  
Metal Precursor ◽  
Ag2s Nanoparticles

Highly luminescent silver indium sulfide (AgInS2) nanoparticles were synthesized by dropwise injection of a sulfur precursor solution into a cationic metal precursor solution. The two-step reaction including the formation of silver sulfide (Ag2S) nanoparticles as an intermediate and their conversion to AgInS2 nanoparticles, occurred during the dropwise injection. The crystal structure of the AgInS2 nanoparticles differed according to the temperature of the metal precursor solution. Specifically, the tetragonal crystal phase was obtained at 140 °C, and the orthorhombic crystal phase was obtained at 180 °C. Furthermore, when the AgInS2 nanoparticles were coated with a gallium sulfide (GaSx) shell, the nanoparticles with both crystal phases emitted a spectrally narrow luminescence, which originated from the band-edge transition of AgInS2. Tetragonal AgInS2 exhibited narrower band-edge emission (full width at half maximum, FWHM = 32.2 nm) and higher photoluminescence (PL) quantum yield (QY) (49.2%) than those of the orthorhombic AgInS2 nanoparticles (FWHM = 37.8 nm, QY = 33.3%). Additional surface passivation by alkylphosphine resulted in higher PL QY (72.3%) with a narrow spectral shape.

Luminescence in Si/Strained Si1−xGex Heterostructures

1995 ◽  
Vol 379 ◽  
Author(s):  
J.C. Sturm ◽  
A. St. Amour ◽  
Y. Lacroix ◽  
M.L.W. Thewalt
Keyword(s):  
Temperature Dependence ◽  
Room Temperature ◽  
Surface Passivation ◽  
Band Edge ◽  
Strained Si ◽  
Edge Luminescence ◽  
Recent Developments ◽  
High Pump ◽  
Band Edge Luminescence ◽  
First Time

ABSTRACTThis paper quickly reviews the structure of band-edge luminescence in Si/strained Si1−xGex heterostructures, and then focusses on two recent developments -- the origin of “deep” sub-bandgap luminescence which is sometimes observed in structures grown by Molecular Beam Epitaxy (MBE) and the understanding of the temperature dependence of the band-edge luminescence (up to room temperature). Strong evidence will be presented that the origin of the deep luminescence is radiation damage, and that generated defects are segregated or trapped in the SilxGex layers. The modelling of the temperature dependence by twocarrier numerical simulation is presented for the first time. The work and experimental data show convincingly that the strength of the luminescence at high temperature is controlled by recombination at the top silicon surface, which in turn can be controlled by surface passivation. At high pump powers and low temperatures, Auger recombination reduces the lifetime in the Si1−xGex layers, and leads to a luminescence vs. temperature which is flat up to 250 K and which is reduced only by a factor of three at room temperature.

Removal of Surface States and Recovery of Band-Edge Emission in InAs Nanowires through Surface Passivation

Nano Letters ◽  
2012 ◽  
Vol 12 (7) ◽  
pp. 3378-3384 ◽  
Author(s):  
M. H. Sun ◽  
H. J. Joyce ◽  
Q. Gao ◽  
H. H. Tan ◽  
C. Jagadish ◽  
...  
Keyword(s):  
Surface Passivation ◽  
Surface States ◽  
Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Inas Nanowires

Surface passivation of a photonic crystal band-edge laser by atomic layer deposition of SiO2and its application for biosensing

Nanoscale ◽  
2015 ◽  
Vol 7 (8) ◽  
pp. 3565-3571 ◽  
Author(s):  
Hyungrae Cha ◽  
Jeongkug Lee ◽  
Luke R. Jordan ◽  
Si Hoon Lee ◽  
Sang-Hyun Oh ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Atomic Layer Deposition ◽  
Surface Passivation ◽  
Atomic Layer ◽  
Band Edge ◽  
Layer Deposition

scholarly journals Enhanced band edge luminescence of ZnO nanorods after surface passivation with ZnS

2018 ◽  
Vol 103 ◽  
pp. 329-337 ◽  
Author(s):  
Asad Ali ◽  
Gul Rahman ◽  
Tahir Ali ◽  
M. Nadeem ◽  
S.K. Hasanain ◽  
...  
Keyword(s):  
Surface Passivation ◽  
Zno Nanorods ◽  
Band Edge ◽  
Edge Luminescence ◽  
Band Edge Luminescence

In Situ Surface Passivation of GaAs by Thermal Nitridation using Metalorganic Vapor Phase Epitaxy

1999 ◽  
Vol 573 ◽  
Author(s):  
Jingxi Sun ◽  
F. J. Himpsel ◽  
A. B. Ellis ◽  
T. F. Kuech
Keyword(s):  
Fermi Level ◽  
Vapor Phase ◽  
Surface Passivation ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Thermal Nitridation ◽  
Surface Fermi Level

ABSTRACTAn ammonia-based, in situ passivation of GaAs surfaces conducted within a metalorganic vapor phase epitaxy reactor is present. The shift of the GaAs surface Fermi level, and hence the surface charge density, resulting from this in situ passivation, has been studied using photoreflectance (PR) spectroscopy. Samples consisting of an undoped GaAs layer on highly doped n-GaAs (UN+) and p-GaAs (UP+) structures allow for the exact determination of the surface Fermi level position using PR These structures were grown by MOVPE and in situ thermal nitridation was performed after growth within the MOVPE system without exposure to the air. After nitridation, the surface Fermi level can be shifted by ∼ 0.23 eV towards the conduction band edge for UN+ structures and by ∼ 0.11 eV towards the valence band edge for UP+ structures from the normally mid-gap ‘pinned’ positions.

The Enhancement of Band Edge Emission from ZnS/Zn(OH)2 Quantum Dots

2000 ◽  
Vol 642 ◽  
Author(s):  
Hatim Mohamed El-Khair ◽  
Ling Xu ◽  
Xinfan Huang ◽  
Minghai Li ◽  
Xiaofeng Gu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Surface Passivation ◽  
Band Edge ◽  
Band Edge Emission ◽  
Trap States ◽  
Edge Emission ◽  
Surface Trap ◽  
Quantum Size ◽  
Transmission Electron

ABSTRACTWurtzite structure monodisperse ZnS quantum dots (QDs) of 1 to 5 nm diameter, synthesized by colloidal chemical method, were confirmed by transmission electron microscopy (TEM) images and electron diffraction (ED) patterns. Enhanced blue shifted band edge emission from Zn(OH)2 capped ZnS QDs with decreasing size has been observed, which indicates the role of inorganic surface passivation and hence supports the quantum size effect. Detectable far-red shifted emission from bare ZnS QDs has been observed when QDs precursors and stabilizer dispersed in solvents with different polarities. This emission is attributed to the surface trap states of different energies.

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