“…There is another reason for the consideration of the work presented in this section. Among various potential shapes (quantum well profiles), there is one which has attracted some research attention recently: this is the case of Pöschl-Teller potential with a constant electron mass [23,24] . Unfortunately, this idealized potential is not realizable in the common, graded ternary alloy based quantum wells, because of the effective mass therein necessarily varies, together with the potential.…”