DX-Center in Se-Doped AlxGa1-xAs

1989 ◽  
Vol 163 ◽  
Author(s):  
Thomas R. Hanak ◽  
Assem M. Bakry ◽  
Richard K. Ahrenkiel ◽  
Michael L. Timmons

AbstractWe report the measurement of the thermal activation energy for the DX- center in Se-doped AlxGa1-xAs grown by metal-organic chemical vapor deposition (MOCVD) for different alloy compositions (x=0.19, 0.23, 0.27, 0.31). The peaks obtained from conventional DLTS are often broad or asymmetric with shoulders on one or both sides. These phenomena often arise from two or more traps which are active in the same temperature range.The capacitive transients are recorded digitally and analyzed directly by applying a nonlinear double exponential fitting routine to the data. This fitting produces two Arrhenius plots and yields the densities of the defect states. From the Arrhenius plots, the capture cross sections at infinite temperature and the thermal activation energies are calculated. These results are then used to simulate the DLTS spectra. Excellent agreement between real and simulated spectra is shown.

Author(s):  
J.L. Batstone

The development of growth techniques such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy during the last fifteen years has resulted in the growth of high quality epitaxial semiconductor thin films for the semiconductor device industry. The III-V and II-VI semiconductors exhibit a wide range of fundamental band gap energies, enabling the fabrication of sophisticated optoelectronic devices such as lasers and electroluminescent displays. However, the radiative efficiency of such devices is strongly affected by the presence of optically and electrically active defects within the epitaxial layer; thus an understanding of factors influencing the defect densities is required.Extended defects such as dislocations, twins, stacking faults and grain boundaries can occur during epitaxial growth to relieve the misfit strain that builds up. Such defects can nucleate either at surfaces or thin film/substrate interfaces and the growth and nucleation events can be determined by in situ transmission electron microscopy (TEM).


2021 ◽  
Vol 15 (6) ◽  
pp. 2170024
Author(s):  
Yuxuan Zhang ◽  
Zhaoying Chen ◽  
Kaitian Zhang ◽  
Zixuan Feng ◽  
Hongping Zhao

ACS Nano ◽  
2020 ◽  
Author(s):  
Assael Cohen ◽  
Avinash Patsha ◽  
Pranab K. Mohapatra ◽  
Miri Kazes ◽  
Kamalakannan Ranganathan ◽  
...  

1997 ◽  
Vol 482 ◽  
Author(s):  
Z-Q. Fang ◽  
J. W. Hemsky ◽  
D. C. Look ◽  
M. P. Mack ◽  
R. J. Molnar ◽  
...  

AbstractA 1-MeV-electron-irradiation (EI) induced trap at Ec-0.18 eV is found in n-type GaN by deep level transient spectroscopy (DLTS) measurements on Schottky barrier diodes, fabricated on both metal-organic-chemical-vapor-deposition and hydride-vapor-phase-epitaxy material grown on sapphire. The 300-K carrier concentrations of the two materials are 2.3 × 1016 cm−3 and 1.3 × 1017 cm−3, respectively. Up to an irradiation dose of 1 × 1015 cm−2, the electron concentrations and pre-existing traps in the GaN layers are not significantly affected, while the EI-induced trap is produced at a rate of at least 0.2 cm−1. The DLTS peaks in the two materials are shifted slightly, possibly due to electric-field effects. Comparison with theory suggests that the defect is most likely associated with the N vacancy or Ga interstitial.


2021 ◽  
Vol 118 (16) ◽  
pp. 162109
Author(s):  
Esmat Farzana ◽  
Fikadu Alema ◽  
Wan Ying Ho ◽  
Akhil Mauze ◽  
Takeki Itoh ◽  
...  

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