IDEAL INTERBAND ABSORPTION-SPECTRA IN AN INDIRECT-GAP-SEMICONDUCTOR QUANTUM-WELL

We have derived the expression for an absorption coefficient in a quantum well made of an indirect-gap semiconductor, considering phonon-assisted and no-phonon (alloy-disorder) processes. The absorption coefficient varies as (homega(lambda)BAR-E(g)+/-homega(p)BAR)s, where homega(lambda)BAR (homega(p)BAR) is the photon (phonon) energy and E(g) is the band gap; s = 0 for bound excitonic absorption and s = 1 for band-to-band or continuum-state transitions. For transitions to the excitonic continuum states, the absorption coefficient increases linearly for high values of photon energy.