Capacitance―voltage spectroscopy of In_(0.5)Ga_(0.5)As self-assembled quantum dots in double quantum wells under selective photo-excitation

摘要

Selectively photo-excited C―V spectroscopy has been measured in an In_(0.5)Ga_(0.5)As quantum dots (QDs)-embedded, three barrier―two well heterostructure. By comparing with a theoretical capacitance model, the pure capacitive contribution from In_(0.5)Ga_(0.5)As QDs, due to tunnelling coupling between In_(0.5)Ga_(0.5)As QDs and In_(0.18)Ga_(0.82)As quantum well, has been used to obtain the density of charges from photo-excited In_(0.5)Ga_(0.5)As QDs in a very straightforward manner.