scholarly journals Study of carrier recombination transient characteristics in MOCVD grown GaN dependent on layer thickness

AIP Advances ◽  
2013 ◽  
Vol 3 (11) ◽  
pp. 112128 ◽  
Author(s):  
E. Gaubas ◽  
T. Čeponis ◽  
A. Jasiunas ◽  
E. Jelmakas ◽  
S. Juršėnas ◽  
...  
2010 ◽  
Vol 247 (7) ◽  
pp. 1703-1706 ◽  
Author(s):  
Kęstutis Jarašiūnas ◽  
Tadas Malinauskas ◽  
Saulius Nargelas ◽  
Vytautas Gudelis ◽  
Juozas V. Vaitkus ◽  
...  

1995 ◽  
Vol 377 ◽  
Author(s):  
C. N. Yeh ◽  
D. X. Han ◽  
K. D. Wang ◽  
L. E. McNeil

ABSTRACTBoth photoluminescence (PL) and electroluminescence (EL) energy spectra were studied in the temperature range of 80 to 300 K on a-Si:H p-i-n structures. The EL spectrum depends on several parameters such as the i-layer thickness and the sample structure with or without a buffer layer (b-layer), while the PL spectrum shows no difference when those parameters are varied. Comparing PL and EL in 0.5 μm p-i-n devices with and without a buffer layer, we found that (a) at 80 K, the main-band peak energy is 1.3 eV for PL and 1.2 eV for EL; (b) the PL spectral line shape does not change with the insertion of a buffer layer, but the EL spectra show more enhanced main-band luminescence with the buffer layer; (c) the temperature dependence of the PL intensity shows a slope of 26 K which is similar to that of a-Si:H films, but the EL efficiency shows a weaker temperature dependence that varies with the diode structure.


Author(s):  
J W Steeds

There is a wide range of experimental results related to dislocations in diamond, group IV, II-VI, III-V semiconducting compounds, but few of these come from isolated, well-characterized individual dislocations. We are here concerned with only those results obtained in a transmission electron microscope so that the dislocations responsible were individually imaged. The luminescence properties of the dislocations were studied by cathodoluminescence performed at low temperatures (~30K) achieved by liquid helium cooling. Both spectra and monochromatic cathodoluminescence images have been obtained, in some cases as a function of temperature.There are two aspects of this work. One is mainly of technological significance. By understanding the luminescence properties of dislocations in epitaxial structures, future non-destructive evaluation will be enhanced. The second aim is to arrive at a good detailed understanding of the basic physics associated with carrier recombination near dislocations as revealed by local luminescence properties.


Author(s):  
Alain Claverie ◽  
Zuzanna Liliental-Weber

GaAs layers grown by MBE at low temperatures (in the 200°C range, LT-GaAs) have been reported to have very interesting electronic and transport properties. Previous studies have shown that, before annealing, the crystalline quality of the layers is related to the growth temperature. Lowering the temperature or increasing the layer thickness generally results in some columnar polycrystalline growth. For the best “temperature-thickness” combinations, the layers may be very As rich (up to 1.25%) resulting in an up to 0.15% increase of the lattice parameter, consistent with the excess As. Only after annealing are the technologically important semi-insulating properties of these layers observed. When annealed in As atmosphere at about 600°C a decrease of the lattice parameter to the substrate value is observed. TEM studies show formation of precipitates which are supposed to be As related since the average As concentration remains almost unchanged upon annealing.


Author(s):  
H. Kung ◽  
A.J. Griffin ◽  
Y.C. Lu ◽  
K.E. Sickafus ◽  
T.E. Mitchell ◽  
...  

Materials with compositionally modulated structures have gained much attention recently due to potential improvement in electrical, magnetic and mechanical properties. Specifically, Cu-Nb laminate systems have been extensively studied mainly due to the combination of high strength, and superior thermal and electrical conductivity that can be obtained and optimized for the different applications. The effect of layer thickness on the hardness, residual stress and electrical resistivity has been investigated. In general, increases in hardness and electrical resistivity have been observed with decreasing layer thickness. In addition, reduction in structural scale has caused the formation of a metastable structure which exhibits uniquely different properties. In this study, we report the formation of b.c.c. Cu in highly textured Cu/Nb nanolayers. A series of Cu/Nb nanolayered films, with alternating Cu and Nb layers, were prepared by dc magnetron sputtering onto Si {100} wafers. The nominal total thickness of each layered film was 1 μm. The layer thickness was varied between 1 nm and 500 nm with the volume fraction of the two phases kept constant at 50%. The deposition rates and film densities were determined through a combination of profilometry and ion beam analysis techniques. Cross-sectional transmission electron microscopy (XTEM) was used to examine the structure, phase and grain size distribution of the as-sputtered films. A JEOL 3000F high resolution TEM was used to characterize the microstructure.


Author(s):  
Masahiro Ito ◽  
Yuitch Iwagaki ◽  
Hiroshi Murakami ◽  
Kenji Nemoto ◽  
Masato Yamamoto ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document