Scanning tunneling microscopy and spectroscopy of InAsP/InP(001) quantum dots

InAsP/InP(001) quantum dots (QDs) grown by metal organic chemical vapor deposition (MOCVD) are very interesting nanostructures for future applications due to their emission in the C-band telecommunications window. The structural and electronic properties of InAsP/InP(001) quantum dots are investigated by cross-sectional scanning tunneling microscopy and spectroscopy at 77K (X-STM/STS). Spatially and energetically resolved differential conductance maps were acquired on several dots, yielding the spatial variations of their discrete local density of states (LDOS). In contrast to previous InAs/GaAs(001) studies, we were able to observe a large number of discrete electronic states for the InAsP/InP(001) system. We present here wave functions images for the electronic round state and four excited states which are separated by typically 50 meV from each other. At last, we present some highly energetically resolved spectroscopic measurements performed at 4K.