Electronic structure of cleaved InAsP/InP(001) quantum dots measured by scanning tunneling spectroscopy

摘要

We investigate the structural and electronic properties of cleaved InAsP quantum dots grown by metal organic chemical vapor deposition on a (001) InP substrate by means of cross-sectional scanning tunneling microscopy and spectroscopy. We performed spatially and energetically resolved differential conductance measurements on several dots and thus mapped their electronic wave functions. Five distinct quantum dot energy levels are identified, all of them strongly confined inside the quantum dot. We further discuss the structural characteristics inferred from topographical images in the specific case of parallelogram-based InAsP/InP(001) quantum dots as a mean of investigating the size of a buried quantum dot.