ESTIMATION OF CRITICAL THICKNESS AND BAND LINEUPS IN ZNCDSE ZNSSE STRAINED-LAYER SYSTEM FOR DESIGN OF CARRIER CONFINEMENT QUANTUM-WELL STRUCTURES

For the fabrication of practical single and multiple semiconductor quantum wells (QWs) capable of confining carriers in the well layers, it is essential that the compositions and thicknesses of constituent layers be suitably chosen to yield sufficiently large conduction and valence band offsets between well and barrier layers, and to avoid lattice relaxation. In this paper we present a guideline for the design of strained-layer ZnCdSe/ZnSSe carrier confinement QWs which satisfy such requirements, based on the estimations of critical thicknesses and band lineups of the structures. From the results obtained here, ZnCdSe/ZnSSe QWs are demonstrated to be eminently suitable for applications to optoelectronic devices operating in the blue-green region of the spectrum.