Y. ZHANG, Y. WANG
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973
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and second energy band gaps and the equal well-barrier
width d. The first energy band gap as the functions of
equal well-barrier width (Figure 8(a)) can be described
as 0.18
10.5e 5.51y, and the second relation (Figure
x
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8(b)) can be given as function 0.47
65e 1.55. It
21.y
x
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can be concluded from Figur rgy e 8 that the first ene
band gap decreases exponentially with the well-barrier
width d while the second energy band gap still shows an
exponential increase with the well-barrier width for
aequilate MQW structure when the well depth is kept
constant.
The inc
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rease of well-barrier width is equivalent to the
diminution of well depth. It leads to weakened quantum
effect and the decrease of the first energy band gap width.
On the other hand, due to the diminution of well depth,
the electrons leap across the barrier more easily, thus
leading to the enhancement of correlating effect of elec-
trons between the well and the barrier which further re-
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4. Conclusion
features of MQW with different well
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