We make a quantum well by sandwiching a 6 nm layer of gaas (eg = 1.43 ev) between two alas with a bandgap of 2.18 ev. assume 2/3 of the bandgap difference appears as conduction band discontinuity, and the rest in the conduction band. the electron and hole effective masses in gaas are 0.67m0 and 0.5m0, respectively. if led is made out of this heterostructures, what is the lowest photon energy that can be emitted from this gaas layer? if a photodetector is made out of this, what is the longest wavelength that can be detected? assume the infinite potential well in your calculation