Tamm states in superlattices

We present experimental results on the localized "surface" states, known as Tamm states, in superlattices. A terminating layer of AlyGa1-yAs on GaAs/AlxGa1-xAs As superlattices produced Tamm states at the states at the interface, which are observed by interaband optical transitions. Results clearly show the presence of localized Tamm states, either above or below the miniband states depending on the composition of the terminating layer, and their interaction with other extended superlattice states. © 1992.