Enhancedk‖filtering effects in ballistic electron emission experiments

Abstract

Double barrier resonant tunneling diodes ͑DBRTD's͒ buried below an Au/GaAs interface usually lead to a linear increase in the spectra obtained in ballistic electron emission microscopy/spectroscopy experiments. If grown directly below the Au/GaAs interface the spectrum changes to a clear steplike shape, which has been attributed to lateral wave-vector k ʈ filtering effects. In this paper, this assertion is tested and quantified by a systematic theoretical study of these structures in terms of a coherent scattering approach as well as magnetotunneling experiments. The calculations show that the enhanced k ʈ filtering is a result of the disordered Au/GaAs interface. The filtering effect is only observed for DBRTD's grown directly beneath the Au/GaAs interface. It vanishes if the DBRTD's are capped with 10 nm or more of GaAs. The calculated k ʈ -filter width agrees well with the Shubnikov-de-Haas-like oscillations obtained from magnetotunneling experiments.

Hot electron spectroscopy and microscopy

“…Additionally, the transport behaviour through single barriers [81,82], resonant tunnelling double barriers [83,84] and superlattices [85,86] have been studied extensively. The first report of the direct detection of quantum confined states in buried AlGaAs-GaAs-AlGaAs double-barrier resonant tunnelling diodes (DBRTDs) was given by Sajoto and co-workers [83].…”

“…This linear behaviour was also confirmed by other groups in various experiments and is since then regarded as typical for buried RTDs. For instance, Strahberger et al [84] presented a detailed experimental and theoretical study on AlGaAs-GaAs DBRTDs, showing the effects of the k xy momentum conservation on the transmission through buried and sub-surface RTDs, respectively. Smoliner et al [86] also demonstrated the effect of the electron refraction on the transmission through buried AlGaAs-GaAs superlattices.…”

“…Additionally, the transport behaviour through single barriers [81,82], resonant tunnelling double barriers [83,84] and superlattices [85,86] have been studied extensively.…”

Self-consistent theory of current and voltage noise in multimode ballistic conductors

“…(see, e.g., Refs. 23,24,25,26). The particular case of a threedimensional (3D) Fermi-Dirac injection has also been addressed.…”