VERY LARGE BLUE AND RED STARK SHIFTS OF THE EXCITONIC-TRANSITION IN INGAAS-INP-INASP ANTISYMMETRIC COUPLED QUANTUM-WELLS

A new strained InGaAs-InP-InAsP antisymmetric coupled quantum well (CQ W) structure with both very large blue and red quantum-confined Stark shifts for the first heavy-hole-to-electron excitonic transition, E(hh 1) --> E(e1), is studied theoretically in this paper. In the antisymme tric coupled quantum well, an antisymmetric-like pair of potential pro files between the shallow-deep conduction band profile and the deep-sh allow valence band profile are formed. The sub-band eigen-energies, E, and the associated envelope wave functions in the CQW structures with or without an applied electric field are calculated by the transfer-m atrix method. The effect of strain on the pseudomorphic layers has bee n taken into account. Results indicate that the strained InGaAs-InP-In AsP antisymmetric CQW structure exhibits significant enhancement of th e blue and red Stark effects in the E(hh1) --> E(e1) transition. The i nfluences of various antisymmetric CQW structural parameters, such as the total well width, the individual well width, the central barrier t hickness and the composition of the strained layer on the quantum-conf ined Stark shift, as well as the envelope wave function overlap, are s tudied systematically. These strong Stark effects in the antisymmetric CQW structure may have potential applications in sophisticated new el ectronic devices, such as optical switching devices.