Influences of the spacer layer growth temperature on multilayer InAs/GaAs quantum dot structures

The effects of GaAs spacer layer growth temperature on the properties of multilayer InAs quantum dot (QD) structures were discussed. As a consequence of surface roughness of the underlying GaAs spacer layers, dislocations nucleate around incoherent islands and extend through subsequent dot layers, for structures with the GaAs spacer layers deposited at low temperature. It was found that the high growth temperature GaAs spacer layers eliminate the surface roughness and suppress the formation of defects. Through the use of the high growth temperature spacer layer (HGTSL), identical QD layers in a 5-layer structure were obtained.