Nanoscale electrical property studies of individual GeSi quantum rings by conductive scanning probe microscopy
State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
Nanoscale Research Letters 2012, 7:659 doi:10.1186/1556-276X-7-659Published: 29 November 2012
The nanoscale electrical properties of individual self-assembled GeSi quantum rings (QRs) were studied by scanning probe microscopy-based techniques. The surface potential distributions of individual GeSi QRs are obtained by scanning Kelvin microscopy (SKM). Ring-shaped work function distributions are observed, presenting that the QRs' rim has a larger work function than the QRs' central hole. By combining the SKM results with those obtained by conductive atomic force microscopy and scanning capacitance microscopy, the correlations between the surface potential, conductance, and carrier density distributions are revealed, and a possible interpretation for the QRs' conductance distributions is suggested.