OPTICAL-PROPERTIES OF QUANTUM DOTS SELF-FORMED IN GAP INP SHORT-PERIOD SUPERLATTICES GROWN ON GAAS (N-11) SUBSTRATES/

Optical properties of multilayer quantum dots (MQDs) self-formed in th e GaP/InP short period superlattice (SL)/InGaP multilayer structures a re investigated by changing SL-period (P) and InGaP barrier thickness (B). By decreasing P, photoluminescence (PL) peak energy shifts toward higher energy due to quantum size effect along the growth direction ( vertical direction). PL linewidth broadening with temperature is reduc ed by decreasing P and B. This improvement is attributed to the reduct ion of potential distribution among QDs and the enhancement of quantum confinement along the vertical direction, and to the enhancement of q uantum confinement due to the vertical coupling effect between QDs. Ve ry small temperature variation of PL peak energy is observed in these MQDs, which is attributed to the existence of the multiaxial strains i n the MQDs. (C) 1998 Elsevier Science B.V. All rights reserved.