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## Energy band gap Eg of AlxGa1-xAs alloys

### Equation

The energy band gap Eg of AlxGa1-xAs alloys depends on the aluminum content x. In the range of x < xc = 0.45 the gap is direct. At x > xc the gap is indirect.
At room temperature (300 K) the dependency of the direct gap on aluminum content x can be calculated by the equation

Eg,dir (x) = 1.422 eV + x 1.2475 eV

In this equation the symbols have the following meaning:

• Eg,dir - direct energy band gap of AlxGa1-xAs for x < 0.45
• x- aluminum fraction of the AlxGa1-xAs alloy

### Numerical values

calculator for Eg(x)   (uses javascript)

Band gap Eg(x) and gap wavelength λg of AlxGa1-xAs alloys at 300 K.

x Eg(x) (eV) λg (nm)
0 1.422 872
0.05 1.48 838
0.10 1.55 800
0.15 1.61 770
0.20 1.67 743
0.25 1.73 717
0.30 1.80 689
0.35 1.86 667
0.40 1.92 646
0.45 1.98 626
0.50 2.00 620
0.60 2.02 614
0.70 2.05 605
0.80 2.07 599
0.90 2.11 588
1.00 2.16 574

- direct band gap
- indirect band gap