scholarly journals Temperature-Dependent Photoluminescence of ZnO Thin Films Grown on Off-Axis SiC Substrates by APMOCVD

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1035
Author(s):  
Ivan Shtepliuk ◽  
Volodymyr Khranovskyy ◽  
Arsenii Ievtushenko ◽  
Rositsa Yakimova
Keyword(s):  
Optical Properties ◽  
Structural Quality ◽  
Organic Chemical ◽  
Zno Films ◽  
Vicinal Surfaces ◽  
Temperature Dependent ◽  
Step Flow ◽  
Step Flow Growth ◽  
First Time ◽  
Temperature Dependent Photoluminescence

The growth of high-quality ZnO layers with optical properties congruent to those of bulk ZnO is still a great challenge. Here, for the first time, we systematically study the morphology and optical properties of ZnO layers grown on SiC substrates with off-cut angles ranging from 0° to 8° by using the atmospheric pressure meta–organic chemical vapor deposition (APMOCVD) technique. Morphology analysis revealed that the formation of the ZnO films on vicinal surfaces with small off-axis angles (1.4°–3.5°) follows the mixed growth mode: from one side, ZnO nucleation still occurs on wide (0001) terraces, but from another side, step-flow growth becomes more apparent with the off-cut angle increasing. We show for the first time that the off-cut angle of 8° provides conditions for step-flow growth of ZnO, resulting in highly improved growth morphology, respectively structural quality. Temperature-dependent photoluminescence (PL) measurements showed a strong dependence of the excitonic emission on the off-cut angle. The dependences of peak parameters for bound exciton and free exciton emissions on temperature were analyzed. The present results provide a correlation between the structural and optical properties of ZnO on vicinal surfaces and can be utilized for controllable ZnO heteroepitaxy on SiC toward device-quality ZnO epitaxial layers with potential applications in nano-optoelectronics.

scholarly journals Photoluminescence excitation spectroscopy of GaN thin layers as a function of temperature

1997 ◽  
Vol 2 ◽  
Author(s):  
C. Guénaud ◽  
E. Deleporte ◽  
M. Voos ◽  
C. Delalande ◽  
B. Beaumont ◽  
...  
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Thin Layers ◽  
Photoluminescence Excitation ◽  
Temperature Dependent ◽  
Electron Hole ◽  
Yellow Band ◽  
Neutral Donor ◽  
Photoluminescence Line ◽  
Temperature Dependent Photoluminescence

We report on photoluminescence and photoluminescence excitation experiments performed on hexagonal GaN layers grown on a Sapphire substrate. Information about extrinsic and intrinsic optical properties have been obtained. We show that, at low temperature, the fundamental A excitons are preferentially involved in the relaxation towards the neutral donor bound exciton photoluminescence line, while electron-hole pairs rather participate in the relaxation towards D0−A0 emission and the yellow band. The relaxation from the A exciton towards the yellow band and D0−A0 emission is made easier by temperature. The band structure of the GaN layers has been determined from temperature dependent photoluminescence excitation spectroscopy: A and C excitons and A continuum band gap have been identified up to 210K.

scholarly journals Fabrication of Self-Assembling AlGaN Quantum Dot on AlGaN Surfaces Using Anti-Surfactant

1999 ◽  
Vol 4 (S1) ◽  
pp. 852-857 ◽  
Author(s):  
H. Hirayama ◽  
Y. Aoyagi ◽  
S. Tanaka
Keyword(s):  
Chemical Vapor ◽  
Organic Chemical ◽  
3 Dimensional ◽  
Step Flow ◽  
Self Assembling ◽  
Metal Organic ◽  
Dot Density ◽  
20 Nm ◽  
Step Flow Growth ◽  
Organic Chemical Vapor Deposition

We report on the first artificial fabrication of self-assembling AlGaN quantum dots (QDs) on AlGaN surfaces using metal organic chemical vapor deposition (MOCVD). The AlGaN QDs are fabricated using a growth mode change from 2-dimensional step-flow growth to 3-dimensional island formation by modifying the AlGaN surface energy with Si anti-surfactant. The average lateral size and the thickness of fabricated AlGaN QDs, as determined by AFM, are approximately 20 nm and 6nm, respectively. The dot density was found to be controlled from 5×1010 cm−2 down to 2×109 cm−2 by increasing the dose of Si anti-surfactant. We obtained the photoluminescence (PL) from AlGaN QDs embedded with Al0.38Ga0.62N capping layers. The Al incorporation in AlGaN QDs was controllable within the range of 1-5 %.

Optical properties of InGaAsBi/GaAs strained quantum wells studied by temperature-dependent photoluminescence

2013 ◽  
Vol 22 (3) ◽  
pp. 037802 ◽  
Author(s):  
Yi Gu ◽  
Yong-Gang Zhang ◽  
Yu-Xin Song ◽  
Hong Ye ◽  
Yuan-Ying Cao ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Temperature Dependent ◽  
Strained Quantum Wells ◽  
Temperature Dependent Photoluminescence

Influence of hydrogen on the step flow growth of GaAs on vicinal surfaces by gas‐source migration enhanced epitaxy

1992 ◽  
Vol 61 (9) ◽  
pp. 1054-1056 ◽  
Author(s):  
H. Asahi ◽  
T. Hisaka ◽  
S. G. Kim ◽  
T. Kaneko ◽  
S. J. Yu ◽  
...  
Keyword(s):  
Vicinal Surfaces ◽  
Step Flow ◽  
Gas Source ◽  
Migration Enhanced Epitaxy ◽  
Step Flow Growth

Molecular beam homoepitaxial growth of MgO(001)

1994 ◽  
Vol 9 (11) ◽  
pp. 2944-2952 ◽  
Author(s):  
S.A. Chambers ◽  
T.T. Tran ◽  
T.A. Hileman
Keyword(s):  
Electron Spectroscopy ◽  
High Speed ◽  
Molecular Beam ◽  
Step Flow ◽  
Homoepitaxial Growth ◽  
Crystallographic Order ◽  
Step Flow Growth ◽  
First Time

We describe homoepitaxial growth and detailed in situ characterization of MgO(001). We have used, for the first time, high-speed Auger electron spectroscopy as a real-time probe of film composition during growth. Excellent short-range and long-range crystallographic order are achieved in films grown to a thickness of several hundred angstroms in the substrate temperature range of 450 °C to 750 °C. Moreover, the films become more laminar as the growth temperature increases, suggesting that MgO grows homoepitaxially by the step-flow growth mechanism at elevated temperature. The surfaces of films grown at 650°and 750 °C are smoother than those obtained by cleaving MgO(001).

Fabrication of Self-Assembling AlGaN Quantum Dot on AlGaN Surfaces Using Anti-Surfactant

1998 ◽  
Vol 537 ◽  
Author(s):  
H. Hirayama ◽  
Y Aoyagi ◽  
S. Tanaka
Keyword(s):  
Chemical Vapor ◽  
Organic Chemical ◽  
3 Dimensional ◽  
Step Flow ◽  
Self Assembling ◽  
Metal Organic ◽  
Dot Density ◽  
20 Nm ◽  
Step Flow Growth ◽  
Organic Chemical Vapor Deposition

AbstractWe report on the first artificial fabrication of self-assembling AlGaN quantum dots (QDs) on AIGaN surfaces using metal organic chemical vapor deposition (MOCVD). The AlGaN QDs are fabricated using a growth mode change from 2-dimensional step-flow growth to 3-dimensional island formation by modifying the AlGaN surface energy with Si anti-surfactant. The average lateral size and the thickness of fabricated AlGaN QDs, as determined by AFM, are approximately 20 nm and 6nm, respectively. The dot density was found to be controlled from 5×1010cm-2 down to 2×109 cm-2 by increasing the dose of Si anti-surfactant. We obtained the photoluminescence (PL) from AlGaN QDs embedded with Al0.38Ga0.62N capping layers. The Al incorporation in AlGaN QDs was controllable within the range of 1-5 %.

Influence of mixed organic cations on the structural and optical properties of lead tri-iodide perovskites

Nanoscale ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 5215-5221 ◽  
Author(s):  
Guotao Pang ◽  
Xiaoqi Lan ◽  
Ruxue Li ◽  
Zhubing He ◽  
Rui Chen
Keyword(s):  
Phase Transition ◽  
Optical Properties ◽  
Organic Cation ◽  
Organic Cations ◽  
Temperature Dependent ◽  
Structural And Optical Properties ◽  
Transition Range ◽  
Phase Transition Range ◽  
Temperature Dependent Photoluminescence

Temperature-dependent photoluminescence in the phase transition range shows that mixed-organic-cation perovskites are more stable than their pure counterparts.

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