Charged and neutral excitons in natural quantum dots in the InAs/GaAs wetting layer

Magnetospectroscopic studies of the InAs/GaAs wetting layer (WL) accompanying self-organized quantum dots (QDs) grown in Stranski–Krastanow mode are presented. Sharp emission lines from “natural” QDs formed in the WL are observed and their evolution in magnetic field is investigated. A quadruplet or a doublet splitting of the emission lines has been observed in magnetic field, which is attributed to a charged and a neutral exciton in a single dot. The metastable transformation of the spectrum from the former to the latter configuration has been observed and explained in terms of the charging of a single dot.