Multi-Quantum-Well Effects on Electronic Structures and Optical Properties of GaP/AlP Superlattice

抄録

The electronic structure and optical transition strengths of the (GaP)_{m_1}(AlP)_{n_1}(GaP)_{m_2} (AlP)_{n_2} … type multi-quantum-well superlattices (MQS's) are calculated with use of the ab initio pseudopotential method within the local density approximation. It is shown that the thickest layers of GaP and AlP are a dominant factor of determining band-gap energy of MQS, while other thin “spacer” layers critically change the transition strengths. Especially, the strong transition strength is obtained when the spacer consists of thinner GaP and AlP layers. Excitonic effect on the photoluminescence is briefly discussed.