Energy Up-Conversion at GaAs-GaInP2 and GaAs-AlGaInP2 Interfaces Caused by Cold Auger Processes

1995 ◽  
Vol 417 ◽  
Author(s):  
F. A. J. M. Driessen ◽  
H. M. Cheong ◽  
A. Mascarehas

AbstractEfficient, low-temperature luminescence at energies far above that of the exciting cw-laser is reported at junctions of GaAs-GaInP2 and GaAs-AlxGa1−x.InP2. The signal originates from the high-band gap layers and disappears only if the excitation energy is tuned below the GaAs band gap, as monitored by up-converted photoluminescence excitation spectroscopy. This shows that the non-linear process is induced by the generation of electrons and holes in the GaAs. Furthermore, it is found that the up-conversion is only observed if the (A1)GaInP2 layers are CuPtB long-range ordered. The reason for this is the inherent presence of metastable states in these ordered alloys. It is argued that cold Auger processes cause the nonlinear effect at these type I interfaces.

2018 ◽  
Vol 10 (3) ◽  
pp. 03005-1-03005-6 ◽  
Author(s):  
Rupali Kulkarni ◽  
◽  
Amit Pawbake ◽  
Ravindra Waykar ◽  
Ashok Jadhawar ◽  
...  

2018 ◽  
Vol 10 (3) ◽  
pp. 03001-1-03001-6 ◽  
Author(s):  
Bharat Gabhale ◽  
◽  
Ashok Jadhawar ◽  
Ajinkya Bhorde ◽  
Shruthi Nair ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fan Liu ◽  
Hua Li ◽  
Junwei Wu ◽  
Bin Wang ◽  
Na Tian ◽  
...  

AbstractThe LOX genes have been identified and characterized in many plant species, but studies on the banana LOX genes are very limited. In this study, we respectively identified 18 MaLOX, 11 MbLOX, and 12 MiLOX genes from the Musa acuminata, M. balbisiana and M. itinerans genome data, investigated their gene structures and characterized the physicochemical properties of their encoded proteins. Banana LOXs showed a preference for using and ending with G/C and their encoded proteins can be classified into 9-LOX, Type I 13-LOX and Type II 13-LOX subfamilies. The expansion of the MaLOXs might result from the combined actions of genome-wide, tandem, and segmental duplications. However, tandem and segmental duplications contribute to the expansion of MbLOXs. Transcriptome data based gene expression analysis showed that MaLOX1, 4, and 7 were highly expressed in fruit and their expression levels were significantly regulated by ethylene. And 11, 12 and 7 MaLOXs were found to be low temperature-, high temperature-, and Fusarium oxysporum f. sp. Cubense tropical race 4 (FocTR4)-responsive, respectively. MaLOX8, 9 and 13 are responsive to all the three stresses, MaLOX4 and MaLOX12 are high temperature- and FocTR4-responsive; MaLOX6 and MaLOX17 are significantly induced by low temperature and FocTR4; and the expression of MaLOX7 and MaLOX16 are only affected by high temperature. Quantitative real-time PCR (qRT-PCR) analysis revealed that the expression levels of several MaLOXs are regulated by MeJA and FocTR4, indicating that they can increase the resistance of banana by regulating the JA pathway. Additionally, the weighted gene co-expression network analysis (WGCNA) of MaLOXs revealed 3 models respectively for 5 (MaLOX7-11), 3 (MaLOX6, 13, and 17), and 1 (MaLOX12) MaLOX genes. Our findings can provide valuable information for the characterization, evolution, diversity and functionality of MaLOX, MbLOX and MiLOX genes and are helpful for understanding the roles of LOXs in banana growth and development and adaptations to different stresses.


2009 ◽  
Vol 67 ◽  
pp. 191-196 ◽  
Author(s):  
Lubna Hashmi ◽  
M.S. Qureshi ◽  
R.N. Dubey ◽  
M.M. Malik ◽  
Ishrat Alim ◽  
...  

A broad range of II-VI materials has been investigated in order to produce light in the full visible range for optoelectronic applications. The present investigation was carried out for the spectroscopic analysis and synthesis of wide band gap cadmium sulfide nanoparticles. Large-band gap semiconductors have the added advantage in that; they can support higher electric field before breaking down, which means that they can be used for high-power electronic devices.Synthesis has been carried out using colloidal synthesis technique at low temperature. The size, stabilization and optical properties were studied using UV-vis Spectrophotometer and Spectroflourometer. Further, the structural studies of synthesized powder were carried out using X-ray diffraction technique; which also confirms the formation of desired product. The capping ligand and the impurities present in the sample were characterized by Fourier transform infra red spectroscopy. Synthesized CdS powder dispersed in aqueous media gave the value of 193 nm for the onset wavelength using UV-vis spectrophotometer, which is significantly blue-shifted compared to bulk CdS and shows the quantum confinement effect. From the onset wavelength the radius of CdS quantum dot calculated using the Brus equation was found to be ca. 0.7 nm.


2014 ◽  
Vol 47 (13) ◽  
pp. 135105 ◽  
Author(s):  
Se Jin Park ◽  
Yunae Cho ◽  
Sung Hwan Moon ◽  
Ji Eun Kim ◽  
Doh-Kwon Lee ◽  
...  

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