2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/186281We consider the specific models of Zhu-Kroemer and BenDaniel-Duke in a sech$^{2}$-mass background and point out interesting correspondences with the stationary 1-soliton and 2-soliton solutions of the KdV equation in a supersymmetric framework.8 Pages, Latex version, Two new references are added, To appear in J.Phys.A (Fast Track Communication)Quantum PhysicsHigh Energy Physics - TheoryMathematical Physicstext