Tip-induced band bending by scanning tunneling spectroscopy of the states of the tip-induced quantum dot on InAs(110)

Abstract

We analyze the quantized states of the tip-induced quantum dot appearing in scanning tunneling spectroscopy ͑STS͒ on n-type InAs͑110͒ (N D ϭ2ϫ10 16 cm Ϫ3 ). STS at negative sample bias ͑Ϫ200-0 mV͒ is used to determine the state energies. The analysis of the spectra indicates that the z-quantization leads to one or two quantized states while a ladder of states due to the lateral confinement is observed. The magnetic-field dependence ͑0-6 T͒ shows the expected splitting of the first excited state in quantitative agreement with Hartree calculations. If an ionized dopant is located in the center of the quantum dot, a reduction in energy and a change in intensity of the single-particle ground state is found, which is also in quantitative agreement with Hartree calculations. The analysis of the tip-induced states can be used to reconstruct the shape of the tipinduced band bending. ͓S0163-1829͑99͒03511-0͔

Intrinsic electronic properties of high-quality wurtzite InN

“…1(a)] and hence free of extrinsic states. Therefore, the electric field applied between the tip and the negatively biased sample penetrates partially into the semiconductor and induces a so-called tip-induced band bending [29][30][31]. This leads to a downward band bending at negative voltages resulting in a tip-induced electron accumulation in the conduction band.…”

A prospective: Quantitative scanning tunneling spectroscopy of semiconductor surfaces

“…7 Over the past decade, much work has been performed to enable quantitative interpretation of tunneling spectra of semiconductors. 8,9,10,11,12,13,14,15,16 What makes this task difficult? Primarily the fact that the semiconductor acts as a dielectric, with some of the applied voltage between sample and tip being dropped within the semiconductor itself, as pictured in Fig.…”

Band structure related wave-function symmetry of amphoteric Si dopants in GaAs

“…It is centered on the projected dopant atom position. The protrusion is surrounded by a dark halo which is the topographic image of charge density oscillations (CDOs) around the donor in the nearly free electron gas of the accumulation layer [26,27,28]. The donor is screened by the tip induced states (TIS) of the accumulation layer.…”

“…The above mentioned tip induced states (TIS) are visualized. The dI/dV-map shows charge density oscillations of the nearly free electron gas [26,27,28]. Both donor and acceptor represent scattering centers within this electron gas.…”