Nanoscale electrical property studies of individual GeSi quantum rings by conductive scanning probe microscopy

Abstract

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.

Layer‐Number‐Dependent Electronic and Optoelectronic Properties of 2D WSe2‐Organic Hybrid Heterojunction

“…The threshold voltage (determined at 1.5 nA) increases as a function of layer number, from ≈0.95 V (2L) to ≈1.7 V (6L). The electron affinity (i.e., CBM) of 1L WSe 2 (Φ 1L ≈ 3.70 eV) is relatively smaller than the work functions of the probe tip (Φ tip ≈ 5.05 eV) and ITO (Φ ITO ≈ 4.75 eV) (Figure b and Figure a inset), rendering a Schottky contact under equilibrium conditions. We adopt the field‐assisted Fowler–Nordheim (FN) tunneling model to elucidate the current dynamics (shown as fitted curves in Figure a; also see the Supporting Information for details) .…”

Charge transport mechanisms and memory effects in amorphous TaN x thin films

“…[31,32]. It is also established that the large surface-to-volume ratio of these nanostructures results in increasing contribution of the surface and space-charge-limited current to the total current [33].…”

“…It is well known for 1-D and 2-D nanostructures, i.e., nanowires, nanorods, and thin films, that the electrical properties may differ greatly from point to point within regions separated by several nanometers, due to differences in charge concentration, defect density, surface band bending, etc. [ 31 , 32 ]. It is also established that the large surface-to-volume ratio of these nanostructures results in increasing contribution of the surface and space-charge-limited current to the total current [ 33 ].…”

Carrier Transport Properties of MoS2 Asymmetric Gas Sensor Under Charge Transfer-Based Barrier Modulation

“…1c . We added the work function value (4.85 eV) of PtIr-coated Si tip to get the work function of electrode and channel part [ 30 ]. Then, normalization process was followed by positioning the percentage value of MoS 2 between Pt and Al as shown in Fig.…”