Threading Dislocation Densities in Mismatched Heteroepitaxial (001) Semiconductors

1990 ◽  
Vol 209 ◽  
Author(s):  
J. E. Ayers ◽  
S.K. Ghandhi ◽  
L. J. Schowalter

ABSTRACTIn this paper we propose a theory which accounts for the thickness dependence of threading dislocation densities in mismatched heteroepitaxial (001) semiconductors. This theory predicts that, for thick, planar, highly-mismatched heteroepitaxial layers with equilibrium strain, the threading dislocation density should be proportional to f/h, where f is thelattice mismatch and h is the film thickness. These predictions are in good agreement with experimental resultsin the GaAs on Si(001) system.

1995 ◽  
Vol 378 ◽  
Author(s):  
G. Kissinger ◽  
T. Morgenstern ◽  
G. Morgenstern ◽  
H. B. Erzgräber ◽  
H. Richter

AbstractStepwise equilibrated graded GexSii-x (x≤0.2) buffers with threading dislocation densities between 102 and 103 cm−2 on the whole area of 4 inch silicon wafers were grown and studied by transmission electron microscopy, defect etching, atomic force microscopy and photoluminescence spectroscopy.


1997 ◽  
Vol 76 (4) ◽  
pp. 807-835 ◽  
Author(s):  
G. E. Beltz ◽  
M. Chang ◽  
J. S. Speck ◽  
W. Pompe ◽  
A. E. Romanov

1994 ◽  
Vol 356 ◽  
Author(s):  
C. C. R. Watson ◽  
K. Durose ◽  
E. O’Keefe ◽  
J. M. Hudson ◽  
B. K. Tanner

Epilayers of LPE Cdo.24Hgo.76Te grown on (111)B CdTe and Cdi-xZnxTe substrates have been examined by defect etching and triple axis x-ray diffraction. Defect etching of bevelled layers has shown the threading dislocation density to fall with increasing distance from the heterointerface, for distances <6μm. In thicker regions however a constant ‘background’ dislocation density is observed. Background dislocation densities of ∼ 3 x 105cm-2 and 9 x 104cm-2 have been measured for layers grown on CdTe and Cdo.96Zn0.04Te respectively, this is compared with a substrate dislocation density of ∼ 3 x 104cm-2 measured in both types of substrates. The increase in the dislocation density within the epilayers compared with the corresponding substrate is discussed. An explanation is also given for the displacement of the peak dislocation density, from the interface to within the layer, observed in the Cd0.76Hg0.24Te / Cd0.96Zn0.04Te system.


1988 ◽  
Vol 27 (Part 2, No. 12) ◽  
pp. L2271-L2273 ◽  
Author(s):  
Takashi Nishioka ◽  
Yoshio Itoh ◽  
Mitsuru Sugo ◽  
Akio Yamamoto ◽  
Masfumi Yamaguchi

2012 ◽  
Vol 1432 ◽  
Author(s):  
Ryan M. France ◽  
Myles A. Steiner

ABSTRACTInitial tests are performed regarding the degradation of lattice-mismatched GaInAs solar cells. 1eV metamorphic GaInAs solar cells with 1-2×106 cm-2 threading dislocation density in the active region are irradiated with an 808 nm laser for 2 weeks time under a variety of temperature and illumination conditions. All devices show a small degradation in Voc that is logarithmic with time. The absolute loss in performance after 2 weeks illuminated at 1300 suns equivalent and 125°C is 7 mV Voc and 0.2% efficiency, showing these devices to be relatively stable. The dark current increases with time and is analyzed with a two-diode model. A GaAs control cell degrades at the same rate, suggesting that the observed degradation mechanism is not related to the additional dislocations in the GaInAs devices.


Sign in / Sign up

Export Citation Format

Share Document