scholarly journals Revealing the nature of low-temperature photoluminescence peaks by laser treatment in van der Waals epitaxially grown WS2 monolayers

Nanoscale ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 4807-4815 ◽  
Author(s):  
V. Orsi Gordo ◽  
M. A. G. Balanta ◽  
Y. Galvão Gobato ◽  
F. S. Covre ◽  
H. V. A. Galeti ◽  
...  
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Laser Treatment ◽  
Van Der Waals ◽  
Low Temperature Photoluminescence

Van der Waals epitaxially grown WS2 monolayers and laser effects on their optical properties are reported.

Physical Properties of Thin Films of GaAs and AlxGa1-xAs Grown by Solid-Arsenic-Based MOCVD

2014 ◽  
Vol 976 ◽  
pp. 25-29
Author(s):  
Roberto Castillo-Ojeda ◽  
Joel Diaz-Reyes ◽  
Miguel Galván-Arellano ◽  
Ramon Peña-Sierra
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Low Temperature ◽  
Growth Process ◽  
Carbon Incorporation ◽  
Infrared Measurements ◽  
Hall Effect Measurements ◽  
Low Temperature Photoluminescence

We have studied the optical properties of GaAs and AlxGa1-xAs thin films using low-temperature photoluminescence and Fourier transform infrared spectroscopy. The GaAs and its alloys were grown by MOCVD using solid arsenic instead of arsine, as the arsenic precursor. The gallium and aluminium precursors were trimethylgallium (TMGa) and trimethylaluminium (TMAl), respectively. Some difficulties for growing AlxGa1-xAs by solid-arsenic-based MOCVD system are the composition homogeneity of the layers and the oxygen and carbon incorporation during the growth process. The composition homogeneity of the films was evaluated by low-temperature photoluminescence. Infrared measurements on the samples allowed the identification of the residual impurities, which are carbon-substitutional, Ga2O3, molecular oxygen, humidity and two unidentified impurities. Samples grown at temperatures lower than 750°C were highly resistive, independently of the ratio V/III used; the samples grown at higher temperatures were n-type, as it was proved by Hall effect measurements.

Optical Properties of Doped Cd1−xMnxTe

1986 ◽  
Vol 89 ◽  
Author(s):  
Y. Lansari ◽  
N. C. Giles ◽  
J. F. Schetzina ◽  
P. Becia ◽  
D. Kaiser
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Spectral Range ◽  
Room Temperature ◽  
Far Infrared ◽  
Optical Quality ◽  
Structural Quality ◽  
Reflectance Measurements ◽  
Low Temperature Photoluminescence

AbstractThe introduction of phosphorus and arsenic dopants into bulk Cd1−xMnx Te crystals grown by the Bridgman-Stockbarger technique has been studieA-with respect to the resulting optical properties. Samples with a Mn composition in the range 0.10 < x < 0.30, both as-grown and annealed, were investigated. A combination of room temperature transmittance and reflectance measurements over the spectral range from the ultraviolet to the far infrared has been used to gain information concerning the structural quality of the samples. Low temperature photoluminescence measurements (1.6−5 K) were used to determine optical quality and excitonic energies.

OPTICAL PROPERTIES OF CdTe/ZnTe ULTRATHIN QUANTUM WELLS GROWN BY ATOMIC LAYER EPITAXY

2002 ◽  
Vol 09 (05n06) ◽  
pp. 1667-1670 ◽  
Author(s):  
M. GARCÍA-ROCHA ◽  
I. HERNÁNDEZ-CALDERÓN
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Quantum Wells ◽  
Gaas Substrate ◽  
Room Temperature ◽  
Diffusion Length ◽  
Substrate Surface ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Low Temperature Photoluminescence

Ultrathin quantum wells (UTQWs) of CdTe within ZnTe barriers were successfully grown by atomic layer epitaxy (ALE) on GaAs(001) substrates. ALE growth of CdTe was performed by alternate exposure of the substrate surface to individual fluxes of Cd and Te. Two different samples with 2-monolayer (ML) (substrate temperature Ts= 270° C ) and 4 ML (Ts = 290° C ) CdTe QWs were grown. Low temperature photoluminescence (PL) experiments exhibited intense and sharp peaks associated to the 2 ML QWs at 2.26 eV. In the case of the nominally 4-ML-thick QW the PL spectrum presented an intense peak around 2.13 eV and two weak features around 2.04 and 1.91 eV. The first peak is attributed to ~ 3 ML QW and the second one to ~ 4 ML QW. The dominance of the 3 ML peak is mainly attributed to Cd loss in the QW due to its substitution by Zn atoms. Due to a high diffusion length of the photogenerated carriers in the barriers, quite weak signals from the ZnTe barriers were observed in both cases. Room temperature (RT) photoreflectance (PR) spectra showed contributions from the CdTe UTQWs, the ZnTe barriers, and the GaAs substrate.

Optical Properties of Mg-GaN, GaN/AlGaN SCH structures, and GaN on ZnO Substrates

1995 ◽  
Vol 395 ◽  
Author(s):  
H. Morkoç ◽  
W. Kim ◽  
Ö. Aktas ◽  
A. Salvador ◽  
A. Botchkarev ◽  
...  
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Room Temperature ◽  
Stimulated Emission ◽  
Lattice Match ◽  
Photoluminescence Emission ◽  
Stacking Order ◽  
Near Ultraviolet ◽  
Side Pumping ◽  
Low Temperature Photoluminescence

ABSTRACTGaN films and GaN/AlGaN heterostructures have been gro wn by MBE. GaN films doped with varying levels of Mg indicate effective mass acceptor at low doping concentrations, as determined from strong photoluminescence emission at about 380 nm. As the Mg concentration is increased the photoluminescence emission line red shifts considerably, indicating the formation of Mg-related or induced complexes whose lifetimes are relatively short. GaN/AlGaN separate confinement heterostructures grown on sapphire show strong near ultraviolet stimulated emission at room temperature in a side-pumping configuration. The pumping threshold for stimulated emission at room temperature was found to be ∼90 kW/cm2. Initial GaN films grown on ZnO substrates show the A exciton in low temperature photoluminescence. ZnO is being considered for nitride growth because of its stacking order and close lattice match.

Optical Properties for ZnSe Epilayer Obtained From Photoluminescience Measurement

2006 ◽  
Vol 321-323 ◽  
pp. 1306-1308
Author(s):  
Sang Youl Lee ◽  
Kwang Joon Hong
Keyword(s):  
Optical Properties ◽  
Binding Energy ◽  
Low Temperature ◽  
Gaas Substrate ◽  
Exciton Peak ◽  
Neutral Donor ◽  
Hot Wall Epitaxy ◽  
Neutral Acceptor ◽  
Low Temperature Photoluminescence ◽  
Zn Vacancy

The ZnSe epilayers were grown on the GaAs substrate by hot wall epitaxy. After the ZnSe epilayers treated in the vacuum-, Zn-, and Se-atmosphere, respectively. The defects of the epilayer were investigated by means of the low-temperature photoluminescence measurement. The dominant peaks at 2.7988 eV and 2.7937 eV obtained from the PL spectrum of the as-grown ZnSe epilayer were found to be consistent with the upper and the lower polariton peak of the exciton, I2 (Do, X), bounded to the neutral donor associated with the Se-vacancy. This donorimpurity binding energy was calculated to be 25.3 meV. The exciton peak, I1 d, at 2.7812 eV was confirmed to be bound to the neutral acceptor corresponded with the Zn-vacancy.

LOW TEMPERATURE PHOTOLUMINESCENCE AND ABSORPTION OF GaxIn1-xAs/ InP

1982 ◽  
Vol 43 (C5) ◽  
pp. C5-383-C5-392 ◽  
Author(s):  
K. H. Goetz ◽  
A. V. Solomonov ◽  
D. Bimberg ◽  
H. Jürgensen ◽  
M. Razeghi ◽  
...  
Keyword(s):  
Low Temperature ◽  
Low Temperature Photoluminescence

A first-principles study on the electronic and optical properties of a type-II C2N/g-ZnO van der Waals heterostructure

2021 ◽  
Vol 23 (6) ◽  
pp. 3963-3973
Author(s):  
Jianxun Song ◽  
Hua Zheng ◽  
Minxia Liu ◽  
Geng Zhang ◽  
Dongxiong Ling ◽  
...  
Keyword(s):  
Optical Properties ◽  
Dft Calculations ◽  
First Principles ◽  
Van Der Waals ◽  
Band Alignment ◽  
Type Ii ◽  
Electronic And Optical Properties ◽  
Direct Bandgap ◽  
Van Der Waals Heterostructure ◽  
Vdw Heterostructure

The structural, electronic and optical properties of a new vdW heterostructure, C2N/g-ZnO, with an intrinsic type-II band alignment and a direct bandgap of 0.89 eV at the Γ point are extensively studied by DFT calculations.

Sign in / Sign up

Export Citation Format

Share Document