5.3 Absorption Coefficient and Material
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Least photon energy required to generate EHP :
Ex.
Eg (Si) = 1.12 eV, g (Si) 1.11m
Eg (Ge) = 0.66 eV, g (Ge) 1.87m
Absorption coefficient and penetration depth are defined the same as that for
evanescence wave :

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