COMPOSITION AND TEMPERATURE-DEPENDENCE OF THE OPTICAL-PROPERTIES OF ZN1-XCDXSE ESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-0.34) BELOW THEFUNDAMENTAL BANDGAP
J. Lee et al., COMPOSITION AND TEMPERATURE-DEPENDENCE OF THE OPTICAL-PROPERTIES OF ZN1-XCDXSE ESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-0.34) BELOW THEFUNDAMENTAL BANDGAP, Applied optics, 36(22), 1997, pp. 5372-5382
The SI-VI ternary semiconductor alloy system Zn1-xCdxSe with 0 less th
an or equal to x less than or equal to 0.2 has important applications
as the active material in blue-green light-emitting diodes;and lasers,
For the wavelength and temperature ranges over which these devices ar
e designed to operate, a knowledge of the optical properties of the al
lays is important. We report the results of spectroscopic ellipsometry
measurements of the real part of the dielectric function epsilon(1) f
or Zn-rich Zn1-xCdxSe layers deposited epitaxially on (100) GaAs. We d
erive compact expressions that allow one to calculate accurate epsilon
(1) spectra from 1.5 eV, the law-energy limit of our ellipsometer, to
E-0 - 0.05 eV, where E-0 is the fundamental bandgap energy, for any co
mposition and temperature within the ranges 0 less than or equal to x
less than or equal to 0.34 and 25 less than or equal to T < 260 degree
s C. Furthermore, we expect that the results can also be extrapolated
to cover the substrate temperature range typically used for the growth
of these films (250-300 degrees C). Hence the results presented here
are also useful in future real-time spectroscopic ellipsometry studies
of Zn1-xCdxSe film growth. (C) 1997 Optical Society of America.