The figure below gives the optical absorption coefficients as a function of photon of several III- V semiconductor materials. Justify why the curves are different for the case of GaAs and Si. Indicate both the shape of the curve and the position of the onset of absorption. 6543 2 1.5 1.1 1.0 0.9 0.8 0.7 0.6 0.5 105 InSb 104 InP Absorption coefficient a (cm-1) 103 102 InAs Ge Si GaAs Gap TTTTTT 10 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 Photon energy (EV) The figure below gives the optical absorption coefficients as a function of photon of several III- V semiconductor materials. Justify why the curves are different for the case of GaAs and Si. Indicate both the shape of the curve and the position of the onset of absorption. 6543 2 1.5 1.1 1.0 0.9 0.8 0.7 0.6 0.5 105 InSb 104 InP Absorption coefficient a (cm-1) 103 102 InAs Ge Si GaAs Gap TTTTTT 10 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 Photon energy (EV)