High density of self-organized quantum dots formed in (GaP)(n)(InP)(m) short period superlattices grown on GaAs (N11)

GaP-n monolayers/InP-m monolayers ((GaP)(n)(InP)(m)) short-period superlattices (SLs) are grown on GaAs (N11) and (100) substrates by gas source molecular beam epitaxy. Scanning tunneling microscopy and transmission electron microscopy observations show that the SLs grown on GaAs (N11)A (N = 2-5) have lateral-composition-modulated dot/columnar structures with a lateral period of about 10-20 nm, while wire structures are formed on GaAs (100). Quantum dots formed in (GaP)(n)(InP)(m)SL/In0.49Ga0.51P multilayers by self-organization exhibit strong 77 K PL with a full width at half-maximum of about 40 meV. Anomalous temperature variation of the PL peak energy is also observed in these self-organized structures.